Surgical instrument

ABSTRACT

A program of instructions for the processor which include: receiving an insertion length of a medical instrument inserted in a patient; and determining a distal end location of the instrument at a target site in the patient from the insertion length. The instrument typically has a straight proximal portion and curved distal portion, lies in a single plane and is a rigid guide member. The instrument is typically inserted and then fixed at a pivot axis outside the patient. The pivot axis is generally aligned with an insertion point at which the instrument is inserted into the patient. The program of instructions may include determining a subsequent location of the distal end associated with pivoting about the pivot axis. The program of instructions may include determining a subsequent location of the distal end associated with axial rotation of the instrument, determining a subsequent location of the distal end associated with linear translation along a length axis of the instrument and/or determining a subsequent movement of the distal end in a single plane about the pivot axis. The pivotal axis is typically a reference point used by the program of instructions in determining subsequent movement of the distal end.

CROSS REFERENCE TO RELATED APPLICATION

This application is a continuation-in-part of and claims the benefit ofpriority from U.S. application Ser. No. 09/827,503, filed Apr. 6, 2001,now U.S. Pat. No. 6,432,112 which is a continuation of U.S. applifcationSer. No. 09/746,853, filed Dec. 21, 2000, now U.S. Pat. No. 6,692,485which is a divisional of U.S. application Ser. No. 09/375,666, now U.S.Pat No. 6,197,017, filed Aug. 17, 1999, which is a continuation of U.S.application Ser. No. 09/028,550 filed Feb. 24, 1998, now abandoned. Thisapplication is also a continuation-in-part of and claims the benefit ofpriority from U.S. application Ser. No. 09/783,637, filed Feb. 14, 2001,which is a continuation of PCT/US00/12553 filed May 9, 2000, whichclaims the benefit of priority of U.S. provisional patent applicationSer. No. 60/133,407, filed May 10, 1999, now abandoned. This applicationis also a continuation-in-part of and claims the benefit of priorityfrom PCT/US01/11376 filed Apr. 6, 2001 which claims priority to U.S.application Ser. Nos. 09/746,853 filed Dec. 21, 2000 now U.S. Pat. No.6,692,485 and 09/827,503 filed Apr. 6, 2001 now U.S. Pat. No. 6,432,112.This application is also a continuation-in-part of and claims thebenefit of priority from U.S. application Ser. Nos. 09/746,853 filedDec. 21, 2000 now U.S. Pat. No. 6,692,485 and 09/827,503 filed Apr. 6,2001 now U.S. Pat. No. 6,432,112. This application is also acontinuation-in-part of and claims the benefit of priority from U.S.application Ser. No. 09/827,643 filed Apr. 6, 2001 now U.S. Pat. No.6,554,844 which claims priority to, inter alia, U.S. provisionalapplication Ser. No. 60/257,869 filed Dec. 21, 2000 and U.S. provisionalapplication Ser. No. 60/195,264 filed Apr. 7, 2000 and is also acontinuation-in-part of PCT/US00/12553 filed May 9, 2000 from which U.S.application Ser No. 09/783,637 filed Feb. 14, 2001 claims priority.

This application also claims the benefit of priority under 35 U.S.C.§§119 and 120 to U.S. Provisional Application Ser. No. 60/293,346 filedMay 24, 2001, U.S. Provisional Application Ser. No. 60/297,087, filedMar. 27, 2001, U.S. Provisional Application Ser. No. 60/313,496 filedAug. 21, 2001, U.S. Provisional Application Ser. No. 60/313,497 filedAug. 21, 2001, U.S. Provisional Application Ser. No. 60/313,495 filedAug. 21, 2001, U.S. Provisional Application Ser. No. 60/269,203 filedFeb. 15, 2001, U.S. Provisional Application Ser. No. 60/269,200 filedFeb. 15, 2001, U.S. Provisional Application Ser. No. 60/276,151 filedMar. 15, 2001, U.S. Provisional Application Ser. No. 60/276,217 filedMar. 15, 2001, U.S. Provisional Application Ser. No. 60/276,086 filedMar. 15, 2001, U.S. Provisional Application Ser. No. 60/6276,152 filedMar. 15, 2001, U.S. Provisional Application Ser. No. 60/257,816 filedDec. 21, 2000, U.S. Provisional Application Ser. No. 60/257,868 filedDec. 21, 2000, U.S. Provisional Application Ser. No. 60/257,867 filedDec. 21, 2000, U.S. Provisional Application Ser. No. 60/257,869 filedDec. 21, 2000.

The disclosures of all of the foregoing applications and U.S. Pat. No.6,197,017 are all incorporated herein by reference in their entirety.

This application further incorporates by reference in its entirety thedisclosures of the following U.S. patent applications which are beingfiled concurrently on the same date herewith, having the followingtitles and Ser. Nos.: 10/014,145—Surgical Instrument;10/012,845—Surgical Instrument; 10/008,964—Surgical Instrument;10/013,046—Surgical Instrument; 10/011,450—Surgical Instrument;10/008,457—Surgical Instrument; 10/008,871—Surgical Instrument;10/023,024—Flexible Instrument; 10/011,371—Flexible Instrument;10/011,449—Flexible Instrument; 10/010,150—Flexible Instrument;10/022,038—Flexible Instrument; and 10/012,586—Flexible Instruments.

BACKGROUND OF THE INVENTION

The present invention relates to surgical instruments and moreparticularly to surgical instruments which are remotely controlled byelectronic control signals generated by a user which are sent to a driveunit which drives mechanically drivable components of a mechanicalapparatus which support a surgical instrument.

SUMMARY OF THE INVENTION

Instrument Support and Mounting

One aspect of the present invention relates to a support member forholding a medical procedure instrument holder in a fixed positionrelative to a patient.

In one embodiment, a medical procedure instrument is provided, includingan instrument holder, an instrument insert, and a support. Theinstrument holder includes an elongated guide member for receiving theinstrument insert. The insert carries on its distal end a medical toolfor executing the medical procedure. The instrument holder is manuallyinsertable into a patient so as to dispose a distal end of the guidemember into a target site in which the procedure is to be executed. Thesupport holds the instrument holder fixed in position relative to thepatient. The instrument holder is held in fixed position in an incisionin the patient between changes of instrument inserts during the courseof a procedure such that trauma or damage which can result fromwithdrawal and re-insertion of another or the same instrument isminimized or eliminated. The distal end of the elongated guide member ispreferably curved and at least the distal end of the instrument insertis flexible to enable the insert to slide through the curved distal endof the guide member.

The instrument insert typically includes an elongated shaft having aproximal end, a distal end and a selected length between the two ends.One or more portions of the elongated shaft along its length, and mosttypically a distal end portion, may comprise a mechanically andcontrollably deformable material such that the portion of the selectedlengths of the shaft which are deformable are controllably bendable orflexible in any one or more of an X, Y and Z axis direction relative tothe axis of the shaft thus providing an additional three degrees offreedom of movement control. Flexible cables, rods or the like which areconnected at one end to a deformable or flexible portion of a shaft andare drivably intercoupled to a controllably drivable drive unit aretypically included for effecting control of the bending or flexing.

In one embodiment, the support includes a bracket that holds aninstrument holder to the support at a fixed reference point. Theinstrument holder is then pivotally supported at this reference pointfrom the bracket.

In various embodiments, the instrument insert is manually engageable anddisengageable with the instrument holder. Generally, the instrumentholder is inserted into the patient first, and then the insert isengaged to the holder, such that the medical tool at the distal end ofthe insert extends beyond the distal end of the guide member at thetarget site. One advantage is to maintain the guide member with itsdistal end at the target site upon withdrawal of the instrument insert.This enables exchange of instrument inserts during the procedure andfacilitates ease of placement of the next instrument insert.

The instrument insert preferably includes a mechanically drivablemechanism for operating the medical tool. The instrument holder alsoincludes a mechanical drive mechanism such that the drive and drivablemechanisms are engageable and disengageable with one another, in orderto enable engagement and disengagement between the insert and holder.Preferably, a drive unit for controlling the instrument insert andholder is disposed remote from the insert and holder, outside of asterile field which may be defined by the area above the operatingtable.

In another embodiment, a medical procedure instrument is provided whichincludes an instrument holder, an instrument insert, and a support. Theinstrument holder includes an elongated guide member for receiving theinsert, the insert carrying at its distal end a medical tool forexecuting a medical procedure. The support holds the instrument holderwith a distal end of the guide member at a target site internal of thepatient. The insert is adapted for ready insertion and withdrawal by wayof the guide member, while the guide member is held at the target site.Again, this facilitates ready exchange of instrument inserts during amedical procedure. The instrument inserts are preferably disposable, sothey can be discarded after a single insertion and withdrawal from thepatient.

In a further embodiment, a remote controlled instrument system isprovided which includes a user interface, an instrument, a support, anda controller. The user interface allows an operator to manually controlan input device. The instrument has at its distal end a tool forcarrying out a procedure, the instrument being manually inserted into apatient so as to dispose the tool at a target site at which theprocedure is to be executed. The support holds a part of the instrumentfixed in position relative to the patient. A controller coupled betweenthe user interface and the instrument is responsive to a remote controlby the operator for controlling the instrument at the target site.

Another embodiment is a method for remotely controlling an instrumenthaving multiple degrees-of-freedom. The instrument is manually insertedinto a patient so as to dispose its distal end at a target site at whicha procedure is to be executed. An instrument holder, that receives theinstrument, is supported stationary relative to the patient during theprocedure so as to maintain the instrument distal end at the targetsite. A user input device is used to remotely control the motion of theinstrument distal end in executing the procedure at the target site.

In a further method embodiment for remotely controlling an instrument,an instrument holder is provided for removably receiving and supportinga disposable instrument insert. The instrument holder is inserted into apatient so as to dispose its distal end at an operative site at whichthe procedure is to be executed. The instrument insert is received inthe holder so as to dispose a tool at the distal end of the insert sothat it extends from the holder and is positioned at the operative site.A user input device remotely controls motion of the insert in executingthe procedure at the operative site. Preferably, the instrument holderis maintained at the operative site as the insert is withdrawn, enablingready exchange of one instrument insert for another.

The invention also provides a medical apparatus for exchanging surgicalinstruments having a selected tool to be positioned at an operative siteof a subject, the apparatus comprising: a guide tube having an opendistal end inserted through an incision of the subject, the guide tubebeing fixedly positioned relative to the subject such that the distalend of the guide tube is fixedly positioned at the operative site, theguide tube being readily manually insertable through the incision; oneor more surgical instruments each having a selected tool mounted at adistal end of the instrument; wherein the one or more surgicalinstruments are readily insertable through the fixedly positioned guidetube such that the selected tool of an instrument is disposed throughthe open distal end of the guide tube at the operative site upon fullinsertion of the surgical instrument, the guide tube having a firstmounting interface and the surgical instruments having a second mountinginterface, the first and second mounting interfaces being readilyengageable with each other to fixedly mount the surgical instrumentswithin the guide tube upon full insertion of the surgical instrument.Such a medical apparatus may further comprise a readily manuallyportable support for fixedly positioning the guide tube in a selectedlocation and orientation relative to the subject, the manually portablesupport being readily fixedly attachable to and detachable from astationary structure on or relative to which the subject is mounted.

These and other embodiments of the instrument, system and method aremore particularly described in the later detailed description section.

Ready Attachability, Couplability and Mountability

Another aspect of the invention is to provide a drive unit or motorassembly which is attachable and detachable from a medical instrumentassembly in order to provide one or more of the features of, positioningthe motor assembly outside a sterile field in which a medical proceduretakes place, increasing portability of the instrument assembly for easeof positioning with respect to the patient and ease of access to thepatient during the procedure, e.g., avoiding bulky and unnecessaryelectromechanical equipment in the sterile field of the procedure so asto increase ease of access to the patient, enabling detachment,sterilization and reusability of certain components of the instrumentassembly and/or detachment and disposability of certain other portionsof the instrument assembly.

In the first embodiment, a medical procedure instrument is provided,including a medical implement and a drive unit. The medical implementincludes a mechanically drivable mechanism intercoupled with the toolused in executing a medical procedure. A drive unit, disposed remotefrom the medical implement, is used for mechanically driving theimplement. The implement is initially decoupled from the drive unit andmanually insertable into a patient so as to dispose the tool at anoperative site within the patient. The medical implement is attachableand detachable with the drive unit for coupling and decoupling themechanically drivable mechanism with the drive unit.

In various preferred embodiments, the medical implement includes aholder and an instrument insert, the holder receiving the insert and theinsert carries the mechanically drivable mechanism. Preferably, theinsert is an integral disposable unit, including a stem section with thetool at its distal end and the mechanically drivable mechanism at itsproximal end.

The drive unit may be an electromechanical unit, and mechanical cablingmay intercouple the drive unit with the mechanically drivable mechanism.Mechanical cabling may be provided to control motion for both theinstrument holder, and the instrument insert. The medical implement maybe remotely controllable by a user, manipulating a manually controllabledevice, which device is connected to the drive unit through anelectrical drive control element.

In another embodiment, a slave station of a robotic surgery system isprovided in which manipulations by a surgeon control motion of asurgical instrument at a slave station. The slave station includes asupport, mechanical cabling, and a plurality of motors. The support ismanually portable and is provided to hold the surgical instrument at aposition over an operating table so that the instrument may be readilydisposed at an operative site. Mechanical cabling is coupled to theinstrument for controlling movement of the instrument. The plurality ofmotors are controlled, by way of a computer interface, and by surgeonmanipulations for driving the mechanical cabling. The mechanical cablingis driven by the plurality of motors in a manner so as to be attachableand detachable from the plurality of motors.

In a preferred embodiment, a two section housing is provided, onehousing section accommodating the ends of the mechanical cabling and theother housing section accommodating the plurality of motors. The twohousing sections are respectively attachable and detachable. A pluralityof coupler spindles supported by the one housing section receive cablesof the mechanical cabling. The plurality of coupler spindles andplurality motors are disposed in aligned arrays. A plurality of couplerdisks of the other housing section are provided, one associated with andsupported by each motor by the plurality of motors. The housing sectionssupport the coupler spindles and the coupler disks in alignedengagement. An engagement element may lock the coupler spindles anddisks against relative rotation.

In a further embodiment, a robotic surgery system is provided, includingan instrument, a support, mechanical cabling, an array of actuators, andan engagement member. The support is manually portable and holds theinstrument over an operating table so that the instrument may bedisposed at an operative site in a patient for remote control thereofvia a computer interface. The mechanical cabling is coupled to theinstrument for controlling movement of the instrument. An array ofelectrically driven actuators is controlled by the computer interfacefor driving the mechanical cabling. An engagement member intercouplesbetween the mechanical cabling and the array of actuators so that themechanical cabling is readily attachable to and detachable from thearray of actuators.

In another aspect of the invention, there is provided a robotic surgeryapparatus comprising: a mechanically drivable surgical instrument foruse at an internal operative site of a subject; an electrically drivendrive unit for driving the surgical instrument; mechanical cablingdrivably intercoupled to the surgical instrument at one end of thecabling; the mechanical cabling having another end which is readilydrivably couplable to and decouplable from the drive unit.

In another aspect of the invention, there is provided a robotic surgeryapparatus comprising: a surgical instrument for use at an internaloperative site of a subject; a mechanically drivable mounting unit onwhich the surgical instrument is mounted, the mounting unit beingdrivably movable outside the operative site of the subject; anelectrically driven drive unit for driving movement of the mountingunit; mechanical cabling drivably intercoupled to the mounting unit atone end of the cabling; the mechanical cabling having another end whichis readily drivably couplable to and decouplable from the drive unit.

In another aspect of the invention there is provided a robotic surgeryapparatus comprising: a mechanically drivable surgical instrument foruse at an internal operative site of a subject; an electrically drivendrive unit for driving the surgical instrument; mechanical cablingdrivably intercoupled to the surgical instrument at one end of thecabling; the drive unit being readily manually portable and readilyattachable to and detachable from a fixed support on or relative towhich the subject is mounted.

These and other embodiments are described in the following detaileddescription section.

Disposability

Another aspect of the invention is to provide a disposable medicalprocedure instrument which includes a mechanically drivable mechanismfor driving a tool.

Disposable or disposability generally means that a device or mechanismis used or intended for a single use without a re-use of thedevice/mechanism and/or without the necessity or intention of a use ofthe device followed by sterilization of the device for an intendedre-use. In practice, a device which is intended for one time or singleuse may be re-used by the user/physician but such re-use more than once,twice or a very limited number of times is not intended for a disposabledevice or mechanism.

In one embodiment, a medical procedure instrument is provided includinga disposable implement and a mounting mechanism interconnected to adrive mechanism. The disposable implement includes a shaft having a toolat its distal end and a mechanically drivable mechanism drivablyinterconnected to the tool. A mounting mechanism, interconnected to thedrive mechanism, enables the mechanically drivable mechanism of theimplement to be removably mounted on the mounting mechanism for drivableinterconnection to the drive mechanism. The shaft is insertable into apatient along a select length of the shaft to position the tool at atarget site in the patient. The shaft together with the mechanicallydrivable mechanism is disposable.

At various embodiments, the drive mechanism is drivably interconnectedto the mounting mechanism at a first interface which is remote from asecond interface at which the mechanically drivable mechanism is mountedto the mounting mechanism. The drive mechanism may include a pluralityof motors, and the mounting mechanism is preferably attachable anddetachable from the drive mechanism. The mounting mechanism may includea guide tube, through which the shaft is inserted into the patient, andwherein the mounting mechanism includes a drivable mechanism formechanically driving the guide tube.

Preferably, the disposable instrument can be removed from the mountingmechanism and discarded after use, while the mounting mechanism can beremoved from the drive mechanism and sterilized for reuse.

The disposable implement is preferably remote controllably drivable by auser via a manually controllable mechanism which is electricallyconnected to the drive mechanism through an electrical drive controlmechanism.

Preferably, the mounting mechanism and the disposable implement aremanually portable in a sterile field, while the drive mechanism isoutside the sterile field.

In another embodiment, a medical procedure instrument is provided whichis a disposable instrument, drivably interconnectable to anddisconnectable from a drive mechanism, the disposable instrumentincluding a mechanically drivable interface, drivably interconnectedthrough a shaft to a tool, the mechanically drivably interface beingdrivably engageable with and disengageable from a second drive interfacewhich is drivably interconnected to the drive mechanism. Preferably, themechanically drivable interface and the shaft are an integral disposableunit. The disposable implement may be remote controllably drivable by auser via a manually controllable mechanism which is electricallyinterconnected to the drive mechanism through an electrical drivecontrol mechanism. The second drive interface may be manually portablein a sterile field. After use, the second drive interface is sterilizedfor reuse. The drive mechanism is outside the sterile field.

In yet another embodiment, a surgical instrument system is providedpositionable within an anatomic body structure and controllable by anoperator. The system contains a guide member, a support, and an integralinstrument member. The guide member has a proximal end and a distal end.The support positions the guide member with the proximal end outside theanatomic body structure and the distal end within the anatomic bodystructure adjacent to the operative site. An integral instrument member,disposable as a unit, includes a mechanical drivable element, a stemsection and a distal tool. The instrument member is removably engageablewith the guide member.

In various embodiments, each of the instrument member and guide memberhas a coupler, the couplers being removably engageable in order to drivethe mechanical drivable element of the instrument member. At least onemotor is provided remote from the guide member and instrument member,and mechanical cabling is provided from the motor to the instrumentmember coupler via the guide member coupler to provide at least 1degree-of-freedom of motion of the instrument member. The couplers mayinclude interengageable wheels. The guide member coupler is pivotal tofacilitate the removable engagement of the guide member and instrumentmember.

In one embodiment, the guide member includes a base piece, and a guidetube extending from the base piece, wherein the coupler is pivotallysupported from the base piece. The instrument member stem section has amechanical cabling extending therethrough from the instrument membercoupler to the distal tool. The instrument member stem section mayinclude sections with different amounts of flexibility. The guide tubeincludes a straight section, and a more distal curved section. When theinstrument member engages with the guide member, the more flexible stemsection is disposed in the guide tube curved section. Anelectromechanical drive member may be provided remote from the guidetube and instrument member, having only mechanical coupling to the guidetube and instrument member. The mechanical coupling may control rotationof the guide tube as well as rotation of the instrument stem within theguide tube.

In another embodiment, a disposable integral medical instrument isprovided including a mechanical coupler, an elongated stem, and a tool.The mechanical coupler is at the proximal end of instrument forreceiving mechanical drive from a drive unit. The elongated stem extendsfrom the mechanical coupler. The tool is disposed at the distal end ofthe elongated stem and is interconnected, via the elongated stem, to themechanical coupler. The elongated stem enables removable insertion in aninstrument holder to position a tool at a target site inside a patientfor performing a medical procedure.

Preferably, the disposable integral medical instrument is attachable toand detachable from an instrument holder in order to couple mechanicaldrive from a remote drive unit. The mechanical coupler includes at leastone interlocking wheel for coupling with the instrument holder. Themechanical coupler includes mechanical cabling extending to the tool.The stem is mounted to enable rotation of the stem relative to themechanical coupler. A wrist joint may be provided at the distal end ofthe stem, coupling to the tool. The elongated stem may have a moredistal flexible section. The instrument may have a means for registeringthe mechanical coupler with an instrument holder.

In another aspect of the invention, there is provided a disposablesurgical instrument comprising: a disposable elongated tube having atool mounted at a distal end of the tube; one or more disposable cablesdrivably interconnected between the tool and a drive unit, the one ormore disposable cables extending through the disposable tube between thetool and a proximal end of the disposable tube. The apparatus preferablyincludes a guide tube having an open distal end, the guide tube beingreadily manually insertable through an incision in a subject to positionthe distal end at an operative site within the subject, the disposableelongated tube being readily insertable through the guide tube toposition the tool through the open distal end of the guide tube. Theapparatus preferably also includes a manually portable support readilyfixedly attachable to and detachable from a stationary structure on orrelative to which the subject is mounted, the guide tube being readilyfixedly interconnectable to and disconnectable from the support forfixedly positioning the distal end of the guide tube at the operativesite. The drive unit is preferably mounted remotely from the operativesite and is drivably interconnected to the one or more cables extendingthrough the disposable tube by one or more cables extending between thedrive unit and the proximal end of the disposable elongated tube.

In another embodiment of the invention there is provided a disposablesurgical instrument comprising: a disposable elongated tube having atool mounted at a distal end of the tube; a disposable mechanicallydrivable interface mounted at a proximal end of the disposable tube, thetool being drivably intercoupled to a drive unit via the disposablemechanically drivable interface.

These and other features of the invention are set forth more fully inthe following detailed description.

Translation and Other Movement Capability

Another aspect of the invention relates to controlled movement of asurgical instrument system having a distal end positionable within apatient. More specifically, the controlled movement may be limited totranslation in a predetermined plane. This controlled movement specifiescertain degrees-of-freedom of the surgical instrument, including a guidetube that receives an instrument member having a tool at its distal end.Such movement may be remotely controlled via computer control inresponse to movements by a surgeon at an input interface.

In one embodiment, a surgical instrument system is provided that isadapted to be inserted through an incision of a patient for operation bya surgeon from outside the patient. The system includes an arm member, asupport for the arm member and an instrument member. The arm member hasa proximal end disposed outside the patient and a distal end internal ofthe patient. A support for the arm member provides controlledtranslation of the arm member with a proximal end thereof movingsubstantially only in a predetermined plane. The instrument member iscarried by the arm member and includes a tool disposed at the distal endof the arm member.

In a preferred embodiment, a controller responsive to a surgeonmanipulation controls movement of the arm member and of the tool. Thesurgeon may be positioned at a master station having an input interface,at which the surgeon manipulates an input device. The controller mayallow a number of degrees-of-freedom of the tool and of the arm member.In one embodiment, the tool has 4 degrees-of-freedom, while the armmember has 3 degrees-of-freedom. More specifically, the arm member mayhave one degree-of-freedom in the predetermined plane. The arm membermay have another degree-of-freedom that is rotation of the arm memberabout a longitudinal axis of the arm member. The arm member may have afurther degree-of-freedom that is linear movement of the arm memberalong the longitudinal axis of the arm member. The tool may have onedegree-of-freedom that is rotation of the instrument member about alongitudinal axis of the instrument member. The tool may have anotherdegree-of-freedom that is pivotal in a second plane orthogonal to thefirst plane. The tool may have jaws and a further degree-of-freedom maybe provided enabling opening and closing of the jaws.

The support for the arm member may include a support post forpositioning the arm member over an operating table upon which a patientis placed. Preferably, the support post positions the arm member at anacute angle to the operating table. The arm member may include a guidetube that receives the instrument member.

In another embodiment, a surgical instrument system is provided adaptedto be inserted through an incision in a patient for operation by asurgeon from outside the patient. The system may include an instrumentmember having a tool at its distal end. The guide member has a guidetube with a proximal end disposed outside the patient and a distal endinternal of the patient. The guide tube has an elongated portion with acentral access of rotation and a distal portion having an end which ispositioned a radial distance away from the central access. The supportfor the guide member provides controlled translation of the guide memberwith the proximal end thereof moving substantially only in apredetermined plane.

In various embodiments, a drive unit is coupled to the guide tube forrotating the guide tube and thereby displacing the tool with respect tothe central access. Preferably, the distal portion of the guide tube iscurved so as to displace the end thereof the radial distance away fromthe central access. When combined with translation in the plane, therotation of the guide tube enables three-dimensional placement of theinstrument tool.

The instrument member may include a coupler for engaging the instrumentmember to the guide member, and an elongated section that is, at least,partially flexible for insertion into the guide tube. The instrumentmember may include in its distal end at least two adjacent link membersintercoupled by way of at least one joint, and at least one cableextending along at least one of the link members for operating theadjacent link member. Separate cable sections may be coupled to oppositesides of the adjacent link members for enabling pivoting in eitherdirection of the adjacent link member relative to the at least one linkmember.

The instrument member can be readily engageable and disengageable withthe guide member and constructed to enable exchange with otherinstrument members. The instrument member may be disposable.

The instrument member may be couplable to and decouplable from a driveunit, the drive unit being controlled by a controller for operating theinstrument member. The drive unit may be disposed remote from a sterilefield in which the patient and instrument member are disposed.

In another embodiment, an instrument system is provided, including auser interface, an instrument, a support, a controller, and a driveunit. A surgeon may manipulate an input device at the user interface.The instrument has a distal end internal of the patient and carrying atits distal end a tool used in executing a procedure at an operative siteof the patient. The support for the instrument includes a pivot at theproximal end of the instrument that limits motion of the proximal end ofthe instrument substantially only in one plane. The controller receivescommands from the user interface for controlling movement of theinstrument. A drive unit intercouples with the controller and theinstrument.

In a preferred embodiment, the instrument includes an adapter and aninstrument insert. The adapter may have a guide tube with an elongatedportion having a longitudinal access of rotation and a distal end thatis positioned a radial distance away from the longitudinal access. Whenthe distal end of the guide tube is curved, the distal end will orbitabout the longitudinal access as the guide tube is rotated under controlfrom the user interface. The insert may be removably couplable with theadapter and include an elongated stem having a tool at its distal end.The adapter and insert may each include a coupler for lateral relativecoupling and decoupling of the adapter and insert. The instrumentcoupler may include a series of wheels that engage with a series ofwheels on the adapter coupler.

The instrument insert may have an elongated stem which includes a moreflexible stem section disposed distally of a less flexible stem section.Alternatively, the full length of the elongated stem may be flexible. Awrist link, intercoupling a more flexible stem section with the tool,provides one degree-of-freedom of the tool.

In another embodiment of the invention there is provided a remotelycontrolled surgical instrument system that is adapted to be insertedthrough an incision of a patient for operation by a surgeon from outsidethe patient in a remote location, the system comprising: an elongatetube having a proximal end disposed outside the patient and a distal endinternal of the patient; a support for the elongate tube that providescontrolled translation of said elongate tube with the proximal endthereof moving substantially only in a predetermined plane; and theelongate tube having an axis and a tool mounted on a distal end of thetube, the elongate tube being curved along a distal length of theelongate tube and controllably rotatable around the axis such that thetool is movable in a circle or an additional two degrees of freedominternal of the patient by rotation of the arm member.

These and other features of the invention are described in the followingdetailed description.

Portability

Another aspect of the invention is to provide readily manually portablecomponents positionable in close proximity to a patient within thesterile field, without unduly reducing access to the patient orotherwise interfering with the procedure.

In one embodiment, a portable remotely controllable surgical instrumentis provided including a shaft, a mounting mechanism and a drive unit. Amanually portable elongated shaft is provided having a proximal end anda distal end manually positionable at an operative site within a subjectupon insertion of the shaft through an incision in the subject. Amanually portable mounting mechanism is readily manually mountable in afixed position outside the patient through the incision, the proximalend of the portable shaft being mounted thereon. A manually portabledrive unit is drivably interconnected through the mounting mechanism toa tool mounted at the distal end of the portable shaft. The drive unitis readily manually positionable at a selected position outside thepatient.

In various embodiments, the drive unit is controllably drivable by acomputer. The proximal end of the portable shaft is readily manuallymountable on the portable mounting mechanism for enabling readilydrivable intercoupling of the tool to the drive unit. The portable shaftmay be disposable. The drive unit may be readily manually mountable at aposition remote from the incision.

In another embodiment, there is provided a portable remotelycontrollable surgical apparatus comprising: a manually portableelongated shaft having a proximal end and a distal end manuallypositionable at an operative site within a subject upon insertion of theshaft through an incision in the subject; a manually portable mountingmechanism being readily manually mountable in a fixed position outsidethe patient near the incision, the proximal end of the portableelongated shaft being mounted thereon; a manually portable support forfixedly positioning the manually portable mounting mechanism in aselected location relative to the subject, the manually portable supportbeing readily fixedly attachable to and detachable from a stationarystructure on or relative to which the subject is mounted. A portabledrive unit is preferably drivably intercoupled through the mountingmechanism to a tool mounted at the distal end of the portable shaft;wherein the drive unit is readily positionable at a selected positionoutside and remote from the incision. The surgical instrument mayinclude one or more mechanically drivable components drivablyintercoupled to a drive unit, the apparatus further comprisingmechanical cabling drivably coupled to the one or more components at oneend of the cabling, the mechanical cabling being readily drivablycouplable to and decouplable from the drive unit at another end of themechanical cabling.

In another embodiment there is provided a portable remotely controllablesurgical apparatus comprising: a manually portable elongated shafthaving a proximal end and a distal end manually positionable at anoperative site within a subject upon insertion of the shaft through anincision in the subject; a manually portable mounting mechanism beingreadily manually mountable in a fixed position outside the patient nearthe incision, the proximal end of the portable elongated shaft beingmounted thereon; a portable drive unit drivably interconnected to theportable elongated shaft through the mounting mechanism; mechanicalcabling drivably coupled to the mounting mechanism at one end of thecabling and readily drivably couplable to and decouplable from theportable drive unit at another end of the cabling. The mountingmechanism typically includes one or more mechanically drivablecomponents for moving the mounting mechanism outside the subject, theone or more mechanically drivable components being drivablyinterconnected to the drive unit through the mechanical cabling.

These and other features of the invention are set forth in greaterdetail in the following detailed description section.

User Control Apparatus

Another aspect of the invention is to provide, in a master/slave surgerysystem, a master station which includes upper and lower positionerassemblies, movably connected, including an arm assembly with a distalhand assembly for engagement by the surgeon's hand.

In one embodiment, a master station is adapted to be manuallymanipulated by a surgeon to, in turn, control motion to a slave stationat which is disposed a surgical instrument. The master station includesa lower positioner assembly, an upper positioner assembly and an armassembly. The upper positioner assembly is supported over and inrotational engagement with the lower positioner assembly to enable alateral side-to-side surgical manipulation. An arm assembly has at itsdistal end a hand assembly for engagement by a surgeon's hand, and aproximal end pivotally supported from the upper positioner assembly toenable an orthogonal forward and back surgeon manipulation in adirection substantially orthogonal to the lateral surgeon manipulation.

In various preferred embodiments, the arm assembly includes a proximalarm member and a distal arm member joined by a rotational joint. Aposition encoder is disposed at a rotational joint detects rotation ofthe distal arm member. A pivotal joint connects the hand assembly to thedistal end of the distal arm member, this movement being responsive to apivotal movement of a surgeon's wrist.

The hand assembly may include a base piece with a pair of holderscoupled with a base piece. One of these holder is adapted to receive athumb and the other adapted to hold a forefinger. Each holder maycomprise a metal bar positioned along the thumb or forefinger and aVelcro loop for attaching the thumb or finger to the bar. The handassembly may further include a pair of rotating element pivotallysupported from opposite ends of the base piece. One of these holders issecured to one of the rotating elements so that the surgeon can move oneholder toward and away from the other holder. The pivotal joint thatconnects the hand assembly to the distal end of the distal arm isconnected to the other rotating element, to account for rotationalmotion at the surgeon's wrist.

In another embodiment, a master station of a master/slave surgery systemincludes a base, an arm assembly pivotally supported from the base, anda hand assembly pivotally supported from the arm assembly, wherein thehand assembly includes a finger holder and a thumb holder and whereinthe holders are supported for relative movement therebetween. The handassembly may include a base piece for the holders, wherein the thumbholder is fixed in position relative to a base piece and the fingerholder rotates from the base piece.

In another embodiment, a master station of a master/slave surgery systemincludes a base, an arm assembly pivotally supported from the base, anda hand assembly pivotally supported from the arm assembly, the handassembly including a guide shaft adapted to be grasped by the surgeon,an actuator on the guide shaft, and a multiple rotation joint attachingthe guide shaft to the arm assembly.

In yet another embodiment, a template is provided secured to the supportwhich holds the surgical instrument, for locating the position of thesupport and subsequently the position of the surgical instrument,relative to the incision point of the patient. This enables an accurateplacement of the instrument at an operative site internal to thepatient.

These and other features of the present invention are described ingreater detail in the following detailed description section.

Electronic Controls and Methodology

The invention also provides a method of controlling a surgicalinstrument that is inserted in a patient for facilitating a surgicalprocedure and controlled remotely from an input device manipulated by asurgeon at a user interface, the method comprising the steps of:initializing the position of the surgical instrument without calculatingits original position, and the position of the input device underelectronic control; the initializing including establishing an initialreference position for the input device and an initial referenceposition for the surgical instrument; calculating the current absoluteposition of the input device as it is manipulated by the surgeon;determining the desired position of the surgical instrument based upon:the current position of the input device, the reference position of theinput device, and the reference position of the surgical instrument, andmoving the surgical instrument to the desired position so that theposition of the surgical instrument corresponds to that of the inputdevice. The input device typically has position sensors, and the step ofinitializing includes initializing these position sensors. Theinitializing is preferably to zero. The method may include computing aninitial reference orientation for the input device, computing a desiredorientation for the surgical instrument and/or computing a desiredposition for the surgical instrument. The initializing step may includeperforming a forward kinematic computation from the input device. Themethod may include reading position sensor values and current time. Thecalculating step may include calculating both the position andorientation of the input device. The method may further includecalculating the current orientation of the input device. The step ofdetermining may include performing an inverse kinematic computationand/or a transformation into an earth coordinate system From thetransformation determined joint angles and drive motor angles for thesurgical instrument orientation may be determined.

In another embodiment, there is provided a method of controlling a toolof a surgical instrument that is inserted in a patient for carrying outa surgical procedure and is controlled remotely by way of a controllerfrom an input device at a user interface, the method comprising thesteps of: the input device at an initial reference configuration andunder controller control; setting the surgical instrument in the patientat an initial predefined reference configuration without controllercontrol; calculating the current absolute position of the input device;determining the desired location of the tool by a kinematic computationthat accounts for at least the initial reference configuration of theinput device and the current absolute position of the input device; andmoving the surgical instrument to the desired position so that thelocation of the tool corresponds to that of the input device. The stepof determining may also be based upon the initial referenceconfiguration of the tool.

In another embodiment, there is provided a system for controlling aninstrument that is inserted in a patient to enable a surgical procedureand controlled remotely from an input device controlled by a surgeon ata user interface, the system comprising: a base; a first link rotatablyconnected to the base; an elbow joint for rotatably connecting thesecond link to the first link; a handle; a wrist member connecting thehandle to the distal end of the second link; and a controller coupled toat least the base and links and for receiving signals representative of:a rotational position of the base, a rotational position of the firstlink relative to the base, and a rotational position of the second linkrelative to the first link.

In another embodiment, there is provided a control system for aninstrument that is controlled remotely from an input device, the systemcomprising: a forward kinematics block for computing the position of theinput device; an initialization block for storing an initial referenceposition of the input device; an inverse kinematics block coupled fromthe forward kinematics block and the initialization block for receivinginformation from the forward kinetics block of the current input deviceposition; and a controller block coupled from the inverse kinematicsblock for controlling the position of the instrument in response tomanipulations at the input device. Such a control system may include ascaling block coupled between the forward kinematics block and theinverse kinematics block for scaling motions imparted at the inputdevice. The system may also include an output from the forwardkinematics block directly to the inverse kinematics block representativeof current input device orientation. The system may also include acombining device coupled from the forward kinematics block and theinitialization block to the scaling block for providing a signal to theinverse kinematics block representative of desired instrument position.The input device typically includes a wrist and a handle and theposition of the wrist is expressed in x, y and z coordinates. Theorientation of the handle is typically determined by a series ofcoordinate transformations. Such system may include a transformationmatrix for the handle coordinate frame with respect to a referencecoordinate frame, a transformation matrix R_(wh) for the wrist jointcoordinate with respect to a reference coordinate, and a transformationmatrix R_(hwh) for the handle coordinate with respect to the wristcoordinate. The transformation matrix R_(h) for the handle coordinatewith respect to the reference coordinate may be R_(h)=R_(wh) R_(hwh).

In another embodiment there is provided a method of controlling amedical implement remotely from an input device that is controlled by anoperator, the method comprising the steps of: positioning the medicalimplement at an initial start position at an operative site for thepurpose of facilitating a medical procedure; establishing a fixedposition reference coordinate representative of the initial startposition of the medical implement based upon a base point of theimplement and an active point of the implement being in a known relativedimensional configuration, positioning the input device at an initialstart position; establishing a fixed position reference coordinaterepresentative of the initial start position of the input device;calculating the current position of the input device as it iscontrolled; determining the desired position of the medical implementbased upon; the current position of the input device, the fixed positionreference coordinate of the input device, and the fixed positionreference coordinate of the medical implement, and moving the medicalimplement to the desired position so that the position of the medicalimplement corresponds to that of the input device.

In another embodiment there is provided a method of controlling asurgical instrument remotely from an input device and by way of anelectronic controller, the method comprising the steps of: inserting thesurgical instrument through an incision in the patient so as to disposethe distal end of the instrument at an initial start position;establishing a fixed position reference coordinate system correspondingto a fixed known position on the surgical instrument at the initialstart position of the surgical instrument; positioning the input deviceat an initial start position; establishing a fixed position referencecoordinate system representative of the initial start position of theinput device; calculating the current absolute position of the inputdevice as it is controlled; determining the desired position of thesurgical instrument based upon the current absolute position of theinput device, and the fixed position reference coordinate system for therespective surgical instrument and input device; and moving the surgicalinstrument to the desired position so that the position of the surgicalinstrument corresponds to that of the input device.

The invention also provides a program of instructions for the processorwhich include: receiving an insertion length of a medical instrumentinserted in a patient; and determining a distal end location of theinstrument at a target site in the patient from the insertion length.The instrument typically has a straight proximal portion and curveddistal portion, lies in a single plane and is a rigid guide member. Theinstrument is typically inserted and then fixed at a pivot axis outsidethe patient. The pivot axis is generally aligned with an insertion pointat which the instrument is inserted into the patient. The program ofinstructions may include determining a subsequent location of the distalend associated with pivoting about the pivot axis. The program ofinstructions may include determining a subsequent location of the distalend associated with axial rotation of the instrument, determining asubsequent location of the distal end associated with linear translationalong a length axis of the instrument and/or determining a subsequentmovement of the distal end in a single plane about the pivot axis. Thepivotal axis is typically a reference point used by the program ofinstructions in determining subsequent movement of the distal end.

The invention also provides a processor and a memory device containing aprogram of instructions for the processor which include: receiving acoordinate representative of the desired location of the distal end of amedical instrument at a target site in a patient; and determining fromthe coordinate an insertion length for the medical instrument so as tolocate the distal end at the target site.

These and other features of the present invention are described ingreater detail in the following detailed description section.

DESCRIPTION OF DRAWINGS

FIG. 1 is a perspective view illustrating one embodiment of the roboticsystem of the present invention;

FIGS. 1A-1C are three views of a flexible cannula for use with theembodiment of FIG. 1;

FIG. 2A is a schematic diagram illustrating the degrees-of-freedomassociated with the master station;

FIG. 2B is a schematic diagram illustrating the degrees-of-freedomassociated with the slave station;

FIG. 2C shows a functional schematic diagram of the surgical adaptercomponent of the system of FIG. 1;

FIG. 2D shows a functional schematic diagram of the instrument insertcomponent of the system of FIG. 1;

FIG. 3 is a perspective view of the positioner assembly at the masterstation;

FIG. 4 is an exploded perspective view also of the positioner assemblyat the master station;

FIG. 5 is a partially exploded view of the hand assembly portionassociated with the positioner assembly;

FIG. 6 is a cross-sectional view of the hand assembly as taken alongline 6—6 of FIG. 3;

FIG. 7 is a cross-sectional view at the master station as taken alonglines 7—7 of FIG. 3;

FIG. 7A is a schematic perspective view of the yoke assembly portion ofthe positioner assembly;

FIG. 8 is a perspective view of the slave station;

FIG. 8A is a perspective view of an alternative adjustable clamp memberat the slave station;

FIG. 8B is a top plan view of the clamp of FIG. 8A;

FIG. 8C is a side view of the clamp of FIGS. 8A and 8B as taken alongline 8C—8C of FIG. 8B;

FIG. 8D is a perspective view of a template used with this embodiment;

FIG. 8E is a schematic cabling diagram illustrating one cablearrangement used to operate a tool;

FIG. 8F is an exploded perspective view of another version of the cabledrive mechanism and tool in accordance with the present invention;

FIG. 8G is a schematic perspective view similar to that illustrated inFIG. 8F but specifically showing the cabling construction;

FIG. 8H is a partially broken away front elevational view as taken alongline 8H—8H of FIG. 8F;

FIG. 8I is a top plan cross-sectional view taken along line 8I—8I ofFIG. 8H;

FIG. 8J is a further cross-sectional top plan view as taken along line8J—8J of FIG. 8H,

FIG. 8K is a cross-sectional side view as taken along line 8K—8K of FIG.8H;

FIG. 8L is a cross-sectional rear view of the coupler spindle and diskas taken along line 8L—8L of FIG. 8K.

FIG. 9 is a view at the slave station taken along line 9—9 of FIG. 8;

FIG. 10 is a side elevation view at the slave station taken along line10—10 of FIG. 9;

FIG. 11 is a perspective view at the slave station;

FIG. 11A is a cross-sectional view as taken along line 11A—11A of FIG.11;

FIG. 11B is a cross-sectional view as taken along line 11B—11B of FIG.11A;

FIG. 11C is a cross-sectional view as taken along line 11C—11C of FIG.11A;

FIG. 12 is a cross-sectional view as taken along line 12—12 of FIG. 11;

FIG. 13 is a cross-sectional view as taken along line 13—13 of FIG. 12;

FIG. 14 is a cross-sectional view as taken along line 14—14 of FIG. 12;

FIG. 15 is a perspective view at the slave station showing theinstrument insert being removed from the adapter;

FIG. 15A is a top plan view of the instrument insert itself;

FIG. 16A is a perspective view at the tool as viewed along line 16A—16Aof FIG. 11;

FIG. 16B is an exploded perspective view of the tool of FIG. 16A;

FIG. 16C is a fragmentary perspective view of an alternative toolreferred to as a needle driver;

FIG. 16D is a side elevation view of the needle driver of FIG. 16C;

FIG. 16E is a perspective view of an alternate embodiment of the tooland wrist construction;

FIG. 16F is an exploded perspective view of the construction illustratedin FIG. 16E;

FIG. 16G is a fragmentary perspective view showing a portion of thebending section;

FIG. 16H is a plan view of the flexible wrist member associated with theconstruction of FIGS. 16E-16G.

FIG. 16I is a perspective view of still another embodiment of a flexibleend tool;

FIG. 16J is an exploded perspective view of the construction illustratedin FIG. 16I;

FIG. 16K is a fragmentary perspective view showing further details ofthe bending section;

FIG. 17 is a perspective view of the drive unit at the slave station;

FIG. 17A is a schematic front view of the drive unit at the slavestation;

FIG. 18 is a schematic perspective view of an alternative hand piece foruse at the master station;

FIGS. 19A-19D are schematic diagrams showing alternate positions of theguide tube of the adapter;

FIG. 20 is a block diagram of the controller used with the roboticsystem of this embodiment;

FIG. 21 is a block diagram of further details of the controller,including the module board;

FIG. 22 is a block diagram of a control algorithm in accordance with thepresent embodiment; and

FIGS. 23-28 are a series of schematic diagrams of the input deviceposition and resulting instrument position relating to the algorithmcontrol of the present embodiment.

DETAILED DESCRIPTION

A. Overview of Surgical Robotic System (FIGS. 1-2)

An embodiment of a surgical robotic system of the present invention isillustrated in the accompanying drawings. The described embodiment ispreferably used to perform minimally invasive surgery, but may also beused for other procedures such as endoscopic or open surgicalprocedures.

FIG. 1 illustrates a surgical instrument system 10 that includes amaster station M at which a surgeon 2 manipulates a pair of inputdevices 3, and a slave station S at which is disposed a pair of surgicalinstruments 14. The surgeon is seated in a comfortable chair 4 with hisforearms resting upon armrests 5. His hands manipulate the input devices3 which cause a responsive movement of the surgical instruments 14.

A master assembly 7 is associated with the master station M and a slaveassembly 8 is associated with the slave station S. Assemblies 7 and 8are interconnected by cabling 6 to a controller 9. Controller 9 has oneor more display screens enabling the surgeon to view a target operativesite, at which is disposed a pair of tools 18. The controller furtherincludes a keyboard for inputting commands or data.

As shown in FIG. 1, the slave assembly 8, also referred to as a driveunit, is remote from the operative site and is positioned outside of thesterile field. In this embodiment, the sterile field is defined abovethe plane of the top surface of the operating table T, on which isplaced the patient P. The drive unit 8 is controlled by a computersystem, part of the controller 9. The master station M may also bereferred to as a user interface, whereby commands issued at the userinterface are translated by the computer into an electrical signalreceived by drive unit 8. Each surgical instrument 14, which is tetheredto the drive unit 8 through mechanical cabling, produces a desiredresponsive motion.

Thus, the controller 9 couples the master station M and the slavestation S and is operated in accordance with a computer program oralgorithm, described in further detail later. The controller receives acommand from the input device 3 and controls the movement of thesurgical instrument in a manner responsive to the input manipulation.

With further reference to FIG. 1, associated with the patient P are twoseparate surgical instruments 14, one on either side of an endoscope 13.The endoscope includes a camera mounted on its distal end to remotelyview the operative site. The dashed line circle in FIG. 2B, labeled OS,is an example of the operative site). A second camera may be positionedaway from the site to provide an additional perspective on the medicalprocedure or surgical operation. It may be desirable to provide theendoscope through an orifice or incision other than the one used by thesurgical instrument. Here three separate incisions are shown, two forthe surgical instruments 14, 14 and a centrally disposed incision forthe viewing endoscope 13. A drape over the patient has a single openingfor the three incisions.

Each of the two surgical instruments 14 is generally comprised of twobasic components, an adaptor or guide member 15 and an instrument insertor member 16. The adaptor 15 is a mechanical device, driven by anattached cable array from drive unit 8. The insert 16 extends throughthe adaptor 15 and carries at its distal end the surgical tool 18.Detailed descriptions of the adapter and insert are found in laterdrawings.

Although reference is made to “surgical instrument” it is contemplatedthat this invention also applies to other medical instruments, notnecessarily for surgery. These would include, but are not limited tocatheters and other diagnostic and therapeutic instruments andimplements.

In FIG. 1 there is illustrated cabling 12 coupling the instrument 14 tothe drive unit 8. The cabling 12 is readily attachable and detachablefrom the drive unit 8. The surgical adaptor 15, which supports theinstrument at a fixed reference point is of relatively simpleconstruction and may be designed for a particular surgical applicationsuch as abdominal, cardiac, spinal, arthroscopic, sinus, neural, etc. Asindicated previously, the instrument insert 16 is couplable anddecouplable to the adaptor 15, and provides a means for exchanginginstrument inserts, with then attached tools. The tools may include, forexample, forceps, scissors, needle drivers, electrocautery, etc.

Referring again to FIG. 1, the overall system 10 includes a surgeon'sinterface 11, computer system or controller 9, drive unit 8 and surgicalinstruments 14. Each surgical instrument 14 is comprised of aninstrument insert 16 extending through adapter 15. During use, a surgeonmanipulates the input device 3 at the surgeon's interface 11, whichmanipulation is interpreted by controller 9 to effect a desired motionof the tool 18 within the patient.

Each surgical instrument 14 is mounted on a separate rigid support post19 which is illustrated in FIG. 1 as removably affixed to the side ofthe surgical table T. This mounting arrangement permits the instrumentto remain fixed relative to the patient even if the table isrepositioned. Although two instruments 14 are shown here, the inventioncan be practiced with more or with only a single surgical instrument.

Each surgical instrument 14 is connected to the drive unit 8 by twomechanical cabling (cable-in-conduit) bundles 21 and 22. These bundles21 and 22 terminate at connection modules, illustrated in FIG. 8F, whichare removably attachable to the drive unit 8. Although two cable bundlesare used here, more or fewer cable bundles may be used. Also, the driveunit 8 is preferably located outside the sterile field as shown here,although in other embodiments the drive unit may be draped with asterile barrier so that it may be located within the sterile field.

In a preferred technique for setting up the system, a distal end of thesurgical instrument 14 is manually inserted into the patient through anincision or opening. The instrument 14 is then mounted to the rigid post19 using a mounting bracket 25. The cable bundles 21 and 22 are thenpassed away from the operative area to the drive unit 8. The connectionmodules of the cable bundles are then engaged to the drive unit 8. Oneor more instrument inserts 16 may then be passed through the surgicaladaptor 15, while the adapter remains fixed in position at the operativesite. The surgical instrument 14 provides a number of independentmotions, or degrees-of-freedom, to the tool 18. These degrees-of-freedomare provided by both the surgical adaptor 15 and the instrument insert16.

The surgeon's interface 11 is in electrical communication with thecontroller 9. This electrical control is primarily by way of the cabling6 illustrated in FIG. 1 coupling from the master assembly 7. Cabling 6also couples from the controller 9 to the drive unit 8. The cabling 6 iselectrical cabling. The drive unit 8 however, is in mechanicalcommunication with the instruments 14 in mechanical cabling 21, 22. Themechanical communication with the instrument allows theelectromechanical components to be removed from the operative region,and preferably from the sterile field.

FIG. 2A illustrates the various movements (J1-J7) that occur at themaster station M while FIG. 2B illustrates various movements (J1-J7)that occur at the slave station S. More specific details regarding FIGS.2A and 2B are contained in a later discussion of FIGS. 3-4 (with regardto the master station of FIG. 2A) and FIGS. 8-9 (with regard to theslave station of FIG. 2B).

FIG. 2C is a simplified representation of adaptor 15 of the slavestation, useful in illustrating the three degrees-of-freedom enabled bythe adapter. The adapter as shown in FIG. 2C comprises a generally rigidouter guide tube 200 (corresponding to guide tube 17 in FIG. 2B) throughwhich an inner flexible shaft, carrying a tool 18 at its distal end, isinserted into the patient. The adapter provides three degrees-of-freedomby way of a pivotal joint J1, a linear joint J2, and a rotary joint J3.From a fixed mounting point 23 shown schematically at the top of FIG.2C, the pivotal joint J1 allows the guide tube 200 to pivot about afixed vertical axis 204, while maintaining the tube (both the proximalstraight portion 208 and distal curved portion 202) in a single plane,transverse to pivot axis 204, in which lies central horizontal tube axis201. The linear joint J2, moves the rigid guide tube 200 along this sameaxis 201. The rotary joint J3 rotates the guide tube 200 about the tubeaxis 201. The guide tube 200 has a fixed curve or bend 202 at its distalend 203; as a result the distal end 203 will orbit in a circle about theaxis 201 when the straight portion 208 of the guide tube 200 is rotatedabout its axis 201. Alternatively, the three degrees-of-freedom can beachieved by a structure other than a curve 202, such as by means of ajoint or angular end section. The point is to have the distal end 203 ofthe tube 200 at a location spaced away from the tube axis 201.

FIG. 2C thus shows a schematic view of the three degrees of freedom ofthe rigid curved guide tube 200. In summary, via the pivot 205 the guidetube 200 may rotate in a direction J1 about an axis 204. The guide tube200 may also slide in an axial direction J2 along proximal tube axis 201(via the linear slider) and rotate in a direction J3 about the proximaltube axis 201 (via a rotatable mounting at the guide tube housing). Itis intended that the point 205 at which the axes of linear movement androtation 201 and 204 intersect, be in linear alignment (along axis 204)with the incision point illustrated in dotted outline at 207, at whichthe guide tube enters the patient. Positioning the incision 207 insubstantially vertical linear alignment with point 205 results in lesstrauma to the patient in the area around the incision, because movementof the guide tube 17 near the point 205 is limited.

In addition to the three degrees-of-freedom provided by the guide tube17, the tool 18 may have three additional degrees-of-freedom. This isillustrated schematically in FIG. 2D which shows an inner flexible shaft309, fixed at its proximal end 300, having a straight proximal portion301 and having a curved distal portion 302 with a tool 18 mounted at thedistal end. The shaft 309 has a wrist joint that rotates about axis 306.A pair of pinchers 304, 305 independently rotate as shown (J6 and J7)about horizontal axis 308 to open and close (e.g., to grasp objects).Still further, the inner shaft can be rotated (J4) about the centralaxis of proximal portion 301.

In practice, an instrument insert 16 (carrying the inner shaft 309) ispositioned within the adaptor 15 (including guide tube 17), so that themovements of the insert are added to those of the adaptor. The tool 18at the distal end of insert 16 has two end grips 304 and 305, which arerotatably coupled to wrist link 303, by two rotary joints J6 and J7. Theaxis 308 of the joints J6 and J7 are essentially collinear. The wristlink 303 is coupled to a flexible inner shaft 302 through a rotary jointJ5, whose axis 306 is essentially orthogonal to the axis 308 of jointsJ6 and J7. The inner shaft 309 may have portions of differingflexibility, with distal shaft portion 302 being more flexible thanproximal shaft portion 301. The more rigid shaft portion 301 isrotatably coupled by joint J4 to the instrument insert base 300. Theaxis of joint J4 is essentially co-axial with the rigid shaft 301.Alternatively, the portions 301 and 302 may both be flexible.

Through the combination of movements J1-J3 shown in FIG. 2C, the adaptor15 can position the curved distal end 203 of guide tube 200 to anydesired position in three-dimensional space. By using only a singlepivotal motion (J1), the motion of the adaptor 15 is limited to a singleplane. Furthermore, the fixed pivot axis 204 and the longitudinal axis201 intersect at a fixed point 205. At this fixed point 205, the lateralmotion of the guide tube 200 is minimal, thus minimizing trauma to thepatient at the aligned incision point 207.

The combination of joints J4-J7 shown in FIG. 2D allow the instrumentinsert 16 to be actuated with four degrees-of-freedom. When coupled tothe adaptor 15, the insert and adaptor provide the instrument 14 withseven degrees-of-freedom. Although four degrees-of-freedom are describedhere for the insert 16, it is understood that greater and fewer numbersof degrees-of-freedom are possible with different instrument inserts.For example an energized insert with only one gripper may be useful forelectro-surgery applications, while an insert with an additional linearmotion may provide stapling capability.

FIG. 2B shows in dotted outline a cannula 487, through which the guidetube 17 is inserted at the incision point. Further details of thecannula are illustrated in FIGS. 1A-1C. FIG. 1A is a longitudinalcross-sectional view showing a cannula 180 in position relative to, forexample, an abdominal wall 190 of the patient. FIG. 1B is a schematicview of the guide tube 17 being inserted through the flexible cannula180. FIG. 1C is a schematic view of the guide tube inserted so that theproximal straight section of the tube is positioned at the incisionpoint within the cannula, with the curved distal end of the guide tubeand tool 18 disposed at a target or operative site.

The cannula 180 includes a rigid base 182 and a flexible end or stem184. The base may be constructed of a rigid plastic or metal material,while the stem may be constructed of a flexible plastic material havinga fluted effect as illustrated in FIGS. 1A-1C. The length of the base isshort enough that the curve in the guide tube can easily pass through acenter passage or bore 186 in the base 182. The bore 186 has a largerdiameter than the outer diameter of the guide tube 17 to facilitatepassage of the guide tube through the cannula 180. A diaphragm or valve188 seals the guide tube 17 within the cannula 180.

FIG. 1A shows a cap 192 secured to the proximal end of the base 182 byone or more o-rings 194. Before the guide tube 17 is inserted in cannula180, a plug 196 may be inserted to seal the proximal end of the base182. The plug 196 is secured by a tether 198 to base 182.

In the context of an insertable instrument system, there may generallybe distinguished two types of systems, flexible and rigid. A flexiblesystem would use a flexible shaft, which may be defined as a shaftatraumatically insertable in a body orifice or vessel which issufficiently pliable that it can follow the contours of the body orificeor vessel without causing significant damage to the orifice or vessel.The shaft may have transitions of stiffness along its length, either dueto the inherent characteristics of the material comprising the shaft, orby providing controllable bending points along the shaft. For example,it may be desirable to induce a bend at some point along the length ofthe shaft to make it easier to negotiate a turn in the body orifice. Amechanical bending of the tube may be caused by providing one or moremechanically activatable elements along the shaft at the desired bendingpoint, which a user remotely operates to induce the bending upon demand.The flexible tube may also be caused to bend by engagement with a bodyportion of greater stiffness, which may, for example, cause the tube tobend or loop around when it contacts the more stiffer body portion.Another way to introduce a bend in the flexible shaft is to provide amechanical joint, such as the wrist joint provided adjacent to tool 18as previously described, which, as discussed further, is mechanicallyactuated by mechanical cabling extending from a drive unit to the wristjoint.

One potential difficulty with flexible shafts or tubes as just describedis that it can be difficult to determine the location of any specificportion or the distal end of such shaft or tube within the patient. Incontrast, what is referred to as a rigid system may utilize a rigidguide tube 17 as previously described, for which the position of thedistal end is more easily determined, simply based upon knowing therelevant dimensions of the tube. Thus, in the system previouslydescribed, a fixed pivot point (205 in FIG. 2C) is aligned with anincision point 207. One can determine the position of the rigid guidetube 17, knowing the length from the fixed point to the distal end ofthe guide tube, which is fixed and predetermined based upon the rigidnature of the guide tube, and the known curvature of the distal end ofthe guide tube. The point of entry or incision point serves as a pivotpoint, for which rotation J1 of the guide tube about the fixed axes 204is limited to maintaining the proximal end of the guide tube in a singleplane.

Furthermore, by inserting the more flexible shaft, carrying a tool 18 atits distal end, within the rigid guide tube, the rigid guide tube ineffect defines a location of the flexible shaft and its distal endlocation tool 18.

Also relevant to the present invention is the use of the term“telerobotic” instrument system, in which a physician or medicaloperator is manually manipulating some type of hand tool, such as a joystick, and at the same time is looking at the effect of such manualmanipulation on a tool which is shown on a display screen, such as atelevision or a video display screen, accessible to the operator. Theoperator then can adjust his manual movements in response to visualfeedback he receives by viewing the resulting effect on the tool, shaftguide tube, or the like, shown on the display screen. It is understoodthat the translation of the doctor's manual movement, via a computerprocessor which feeds a drive unit for the inserted instrument, is notlimited to a proportional movement, rather, the movement may be scaledby various amounts, either in a linear fashion or a nonlinear fashion.The scaling factor may depend on where the instrument is located orwhere a specific portion of the instrument is located, or upon therelative rate of movement by the operator. The computer controlledmovement of the guide tube or insert shaft in accordance with thepresent invention, enables a higher precision or finer control over themovement of the instrument components within the patient.

In practice, the physician, surgeon or medical operator would make anincision point, inserting the flexible cannula previously shown. Hewould then manually insert the rigid curved guide tube until the distalpoint of the guide tube was positioned at the operative site. With theguide tube aligned in a single plane, the operator would clamp the guidetube at the support bracket 25 on post 19, to establish the fixedreference pivot point, (205 in FIG. 2C), with the incision point axiallyaligned under the fixed pivot point. The operator would then manuallyinsert the instrument insert through the guide tube until the tool 18 isextended out from the distal end of the guide tube. The wrist joint onthe inner insert shaft is then positioned at a known point, based uponthe known length and curvature of the rigid guide tube and distancealong that length at which the incision point is disposed. Then, aphysician, surgeon or medical operator located at the master station canmanually adjust the hand assembly to cause a responsive movement of theinserted instrument. The computer control decides what the responsivemovement at the instrument is, including one or more of movement of theguide tube, the whole instrument 14, or the flexible inner shaft or thetool at its distal end. A pivotal movement J1 will rotate the proximalend of the guide tube, causing pivoting of the whole instrument 14. Anaxial movement J2 of the whole instrument 14 will reposition theinstrument in the single plane. A rotational movement J3 of just theguide tube results in the end of the guide tube and end of the innershaft being taken out of the plane, following a circular path or orbitin accordance with rotation of the guide tube shaft. These threemovements J1, J2 and J3 are defined as setting the position of the wristjoint 303 of the tool.

The other three movements J4-J7, are defined as setting the orientationof the instrument insert, and more specifically, a direction at whichthe tool is disposed with respect to the wrist joint. Central mechanicalcables in the inner shaft cause motions J5-J7, J5 being the wristmovement and J6-J7 being the jaw movement of the tool. The J4 movementis for rotation of the inner shaft by its proximal axis, within theguide tube. These relative movements, and the position and orientationof the instrument insert, will be further described in a laterdiscussion of an example of the computer algorithm for translating themovement at the master station to a movement at the slave station.

B. The Master Station M (FIGS. 3-7)

At the master station M illustrated in FIG. 1 and shown in furtherdetail in FIG. 3, there are two sets of identical hand controls, oneassociated with each hand of the surgeon. The outputs of both controlsare fed to assembly 7, which is secured to the surgeon's chair 4 by across-brace 40. In FIG. 3, the brace 40 is shown secured to the chairframe 42 by means of adaptor plate 44 and bolts 45. Additional bolts 46,with associated nuts and washers secure the cross-brace 40 in a desiredlateral alignment (see double headed arrow) along the adaptor plate 44.Additional bolts 49 (see FIG. 4) are used for securing the cross-brace40 with a base piece 48. The base piece 48 supports lower and upperpositioner assemblies, as will now be described.

A lower positioner assembly 50 is supported from the base piece 48. Anupper positioner assembly 60 is supported above and in rotationalengagement (see arrow J1 in FIGS. 2A and 4), in a substantiallyhorizontal plane with the lower positioner assembly. This rotationalmovement J1 enables a lateral or side-to-side manipulation by thesurgeon. An arm assembly 90, having a lower proximal end 90A, ispivotally supported (J2) from the upper positioner assembly 60 about asubstantially horizontal axis 60A (see FIGS. 2A and 3) to enablesubstantially vertical surgeon manipulation. The arm assembly 90 has anupper distal end 90B (FIG. 3), carrying a hand assembly 110.

As shown in FIG. 4, the lower positioner assembly 50 includes a basemember 51 that is secured to the base piece 48 by bolts 52. It alsoincludes a bracket 53 that is secured to the base member 51 by means ofbolts 54. The bracket 53 supports a motor/encoder 55. A vertical shaft56 that extends from the upper positioner assembly 60 to the base member51, extends through a passage in the base member 51 and is secured to apulley 57 disposed under the base member 51. A belt 58 engages withpulley 57 and with a further pulley 62 supported from the bracket 53.This further pulley 62 is on a shaft that engages a pulley 59. A furtherbelt 61 intercouples pulley 59 to the shaft of the motor/encoder 55.

In FIGS. 3 and 4, the base member 51 and bracket 53 are stationary;however, upon rotation about J1, drive is applied to the pulleys 57 and59 thus applying drive to the motor/encoder 55. This detects theposition and movement from one position to another of the upperpositioner assembly 60 relative to the lower positioner assembly 50.

The upper positioner assembly 60 has a main support bracket 63,supporting on either side thereof side support brackets 64 and 66. Sidebracket 64 supports a pulley 65, while side bracket 66 supports a pulley67. Above pulley 65 is another pulley 70, while above pulley 67 isanother pulley 72. Pulley 70 is supported on shaft 71, while pulley 72is supported on shaft 73.

Also supported from side support bracket 64 is another motor/encoder 74,disposed on one side of the main support bracket 63. On the other sideof bracket 63 is another motor/encoder 76, supported from side supportbracket 66. Motor/encoder 74 is coupled to the shaft 71 by pulleys 65and 70 and associated belts, such as the belt 75 disposed about pulley65. Similarly, motor/encoder 76 detects rotation of the shaft 73 throughpulleys 67 and 72 by way of two other belts. The pulley 65 is alsosupported on a shaft coupling to pulley 70 supported by side supportbracket 64. A further belt goes about pulley 70 so there is continuityof rotation from the shaft 71 to the motor/encoder 74. These variousbelts and pulleys provide a movement reduction ratio of, for example, 15to 1. This is desirable so that any substantial movements at the masterstation are translated as only slight movements at the slave station,thereby providing a fine and controlled action by the surgeon.

Extending upwardly from main support bracket 63, is arm assembly 90which includes a pair of substantially parallel and spaced apart uprightproximal arms 91 and 92, forming two sides of a parallelogram. Arm 91 isthe main vertical arm, while arm 92 is a tandem or secondary arm. Thebottoms of arms 91 and 92 are captured between side plates 78 and 79.The secondary arm 92 is pivotally supported by pin 81 (see FIG. 4) fromthe forward end of the side plates 78 and 79. The main arm 91 is alsopivotally supported between the side plates 78 and 79, but is adapted torotate with the shaft 71. Thus, any forward and back pivoting J2 of thearm 91 is sensed through the shaft 71 down to the motor/encoder 74. Thismovement J2 in FIGS. 2A and 4 translates the forward and rearward motionat the surgeon's shoulder.

The side plates 78 and 79 pivot on an axis defined by shafts 71 and 73.However, the rotation of the plates 78 and 79 are coupled only to theshaft 73 so that pivotal rotation, in unison, of the side plates 78 and79 is detected by motor/encoder 76. This action is schematicallyillustrated in FIGS. 2A and 4 by J3. Movement J3 represents an up anddown motion of the surgeon's elbow. A counterweight 80 is secured to themore rear end of the side plates 78 and 79, to counter-balance theweight and force of the arm assembly 90.

As depicted in FIGS. 3 and 4, the tops of the arms 91 and 92 arepivotally supported in a bracket 94 by two pivot pins 89. The bracket 94also supports a distal arm 96 of the arm assembly 90. The rotation ofdistal arm 96 is sensed by an encoder 88. Thus, the distal arm 96 isfree to rotate J4 about its longitudinal axis, relative to the arms 91and 92. This rotation J4 translates the rotation of the surgeon'sforearm.

The distal end of distal arm 96 is forked, as indicated at 95 in FIG. 4.The forked end 95 supports disc 97 in a fixed position on shaft 98. Thedisc 97 is fixed in position while the shaft 98 rotates therein;bearings 93 support this rotation. The shaft 98 also supports one end ofpivot member 100, which is part of hand assembly 110. The pivot member100 has at its proximal end a disc 101 that is supported co-axially withthe disc 97, but that rotates relative to the fixed disc 97 (see FIGS. 5and 6). This rotation is sensed by an encoder 99 associated with shaft98. The disc end 101 of the pivot member 100 defines the rotation J5 inFIG. 4, which translates the wrist action of the surgeon, particularlythe up and down wrist action.

The pivot member 100 has at its other end a disc 103 that rotatesco-axially with a disc end 104 of hand piece 105. There is relativerotation between disc 103 and disc 104 about a pivot pin 106 (see FIGS.4 and 6). This relative rotation between the pivot member 100 and thehand piece 105 is detected by a further encoder 109 associated withdiscs 103 and 104. This action translates lateral or side to side (leftand right) action of the surgeon's hand.

At the very distal end of the master station is a forefinger member 112that rotates relative to end 114 of the hand piece 105. As indicated inFIG. 3, the forefinger piece 112 has a Velcro loop 116 for holding thesurgeon's forefinger to the piece 112. Also extending from the handpiece 105 is a fixed position thumb piece 118, with an associated Velcroloop 120. In FIG. 3, motion J7 represents the opening and closingbetween the surgeon's forefinger and thumb.

Reference is now made to FIG. 5, which shows expanded details of thedistal end of the arm assembly. One end of the distal arm 96 couples tothe fork 95; fork 95 supports one end of the pivot member 100. Theencoder 99 detects the position of the pivot member 100 relative to thedistal arm 96. The encoder 109 couples to a shaft adapter 119 anddetects relative displacement between the pivot member 100 and the handpiece 105. The thumb piece 118 is secured to the side piece 125 which,in turn, is secured as part of the hand piece 105. Bolts 126 secure thefinger piece 112 to the rotating disc 130. The distal end encoder 132,with encoding disc 134, detects the relative movement between thesurgeon's thumb and forefinger pieces.

FIG. 6 shows further details of the distal end of the arm assembly.Pivot member 100 is attached to the distal arm 96 and the hand piece105. Further details are shown relating to the encoder 132 and theencoder disc 134. A shaft 140, intercoupling hand piece 105 and disc130, is supported by a bearing 142. The shaft 106 is also supported by abearing 144.

The detailed cross-sectional view of FIG. 7 is taken along lines 7—7 ofFIG. 3. This illustrates the base member 51 with the pulley 57 supportedthereunder by means of the shaft 56. Also illustrated are bearings 147about shaft 56 which permit the main support bracket 63 to pivot (J1).Pulley 57 rotates therewith and its rotation is coupled to the encoder55 for detecting the J1 rotation. FIG. 7 also illustrates themotor/encoder 76, where the separate dashed portions identify motor 76Aand encoder 76B.

FIG. 7 also shows further details of the belt and pulley arrangement.For simplicity, only the pulley 67 and its associated support isdisclosed. Substantially the same construction is used on the other sideof the main support bracket 63 for the mounting of the opposite pulley65. A belt 149 about pulley 72 also engages with pulley 153 fixedlysupported on the shaft 155. The shaft 155 rotates relative to the fixedside support bracket 66, by way of bearings 154. The shaft 155 supportsthe pulley 67. A toothed belt 150 is disposed about pulley 67 to thesmaller pulley 152. The pulley 152 is supported on the shaft of themotor/encoder 76. For the most part all pulleys and belts disclosedherein are toothed so that there is positive engagement and no slippagetherebetween.

In order to provide adjustment of the belts 149 and 150, adjustingscrews are provided. One set of adjusting screws is shown at 157 foradjusting the position of the side support bracket 66 and thus the belt149. Also, there are belt adjusting screws 158 associated with supportplate 159 for adjusting the position of the encoder and thus adjustingthe belt 150.

FIG. 7 also illustrates the pulleys 70 and 72 with their respectivesupport shafts 71 and 73. FIG. 7A shows details of the pulleys 70 and 72and their support structure. The pulley 70 is associated with motion J2.The pulley 72 is associated with motion J3. The pulley 70 and itsassociated shaft 71 rotate with the vertical main shaft or arm 91. Thepulley 72 and its associated shaft 73 rotate independent of the arm 91and instead rotate with the rotation of the side plates 78 and 79. Oneend of shaft 71 is secured with the pulley 70. The other end of theshaft 71 engages a clamp 161, which clamps the other end of the shaft tothe support piece 162 of the main vertical arm 91. The shaft 71 issupported for rotation relative to the main support bracket 63 and theside plates 78, 79 by means of bearings 164.

The opposite pulley 72 and its shaft 73 are supported so that the pulley72 rotates with rotation of the yoke formed by side plates 78 and 79. Aclamp 166 clamps the shaft 73 to the side plate and thus to the rotatingyoke. This yoke actually rotates with the pin of shaft 73. For furthersupport of the shaft 73, there are also provided bearings 168, oneassociated with the support bracket 63 and another associated withsupport piece 162.

Regarding the yoke formed by side plates 78 and 79, at one end thereofis a counterweight 80, as illustrated in FIGS. 4 and 7A. The other endsupports a rotating block 170 (see FIG. 4) that supports the lower endof arm 92 and has oppositely disposed ends of pin 81 rotatably engagedwith that end of the yoke (side plates 78 and 79). Bushings or bearingsmay be provided to allow free rotation of the bottom end of the arm 92in the yoke that captures this arm.

In practice, the following sequence of operations occur at masterstation M. After the instrument 14 has been placed at the properoperative site, the surgeon is seated at the console and presses anactivation button, such as the “enter” button on the keyboard 31 onconsole 9. This causes the arms at the master station to move to apredetermined position where the surgeon can engage thumb and forefingergrips. FIG. 1 shows such an initial location where the arm assemblies 3are essentially pointed forward. This automatic initialization movementis activated by the motors in unit 7 at the master station. Thiscorresponds, in FIG. 2A, to upper arm 96 being essentially horizontaland lower arm 92 being essentially vertical.

While observing the position of the tools on the video display screen30, the surgeon now positions his hand or hands where they appear tomatch the position of the respective tool 18 at the operative site (OSin FIG. 2B). Then, the surgeon may again hit the “enter” key. Thisestablishes a reference location for both the slave instrument and themaster controls. This reference location is discussed later with detailsof controller 9 and an algorithm for controlling the operations betweenthe master and slave stations. This reference location is alsoessentially identified as a fixed position relative to the wrist jointat the distal end of distal arm 96 at pin 98 in FIG. 4 (axis 98A in FIG.2A). This is the initial predefined configuration at the master station,definable with three dimensional coordinates.

Now when the surgeon is ready to carry out the procedure, a thirdkeystroke occurs, which may also be a selection of the “enter” key. Whenthat occurs the motors are activated in the drive unit 8 so that anyfurther movement by the surgeon will initiate a corresponding movementat the slave end of the system.

Reference is now made to FIG. 18 which is a schematic perspective viewof an alternate embodiment of an input device or hand assembly 860A.Rather than providing separate thumb and forefinger members, asillustrated previously, the surgeon's hand is holding a guide shaft861A. On the shaft 861 there is provided a push-button 866A thatactivates an encoder 868A. The guide shaft 861A may be considered moresimilar to an actual surgical instrument intended to be handled directlyby the surgeon in performing unassisted nonrobotic surgery. Thus, thehand piece 860A illustrated in FIG. 18 may be more advantageous to usefor some types of operative procedures.

FIG. 18 illustrates, in addition to the encoder 868A, three otherencoder blocks, 862A, 863A and 864A. These are schematically illustratedas being intercoupled by joints 870A and 871A. All four of theseencoders would provide the same joint movements depicted previously inconnection with joints J4-J7. For example, the button 866A may beactivated by the surgeon to open and close the jaws.

C. The Slave Station S

C1—Slave Overview (FIGS. 8-8D)

Reference is now made to FIG. 8 which is a perspective view illustratingthe present embodiment of the slave station S. A section of the surgicaltabletop T is shown, from which extends the rigid angled post 19 thatsupports the surgical instrument 14 at mounting bracket 25. The driveunit 8 is also supported from the side of the tabletop by an L-shapedbrace 210 that carries an attaching member 212. The brace is suitablysecured to the table T and the drive unit 8 is secured to the attachingmember 212 by means of a clamp 214. A lower vertical arm 19A of therigid support rod 19 is secured to the attaching member 212 by anotherclamping mechanism 216, which mechanism 216 permits vertical adjustmentof the rigid support 19 and attached instrument 14. Horizontaladjustment of the surgical instrument is possible by sliding themounting bracket 25 along an upper horizontal arm 19B of the support rod19. One embodiment of the drive unit 8 is described in further detail inFIG. 17. A preferred embodiment is illustrated in FIGS. 8F-8L.

The clamping bracket 216 has a knob 213 that can be loosened toreposition the support rod 19 and tightened to hold the support rod 19in the desired position. The support rod 19, at its vertical arm 19A,essentially moves up and down through the clamp 216. Similarly, themounting bracket 25 can move along the horizontal arm 19B of the supportrod 19, and be secured at different positions therealong. The clamp 214,which supports the drive unit 8 on the operating table, also has a knob215 which can be loosened to enable the drive unit to be moved todifferent positions along the attaching member 212.

FIG. 8 also shows the cable-in-conduit bundles 21 and 22. The cables inthe bundle 21 primarily control the action of the adapter or guidemember 15. The cables in bundle 22 primarily control the tool 18, alldescribed in further detail below.

FIG. 8 also illustrates a support yoke 220 to which is secured themounting bracket 25, a pivot piece 222, and support rails 224 for acarriage 226. Piece 222 pivots relative to the support yoke 220 aboutpivot pin 225.

FIG. 2B is a schematic representation of the joint movements associatedwith the slave station S. The first joint movement J1 represents apivoting of the instrument 14 about pivot pin 225 at axis 225A. Thesecond joint movement J2 is a transition of the carriage 226 on therails 224, which essentially moves the carriage and instrument 14supported therefrom, in the direction indicated by the arrow 227. Thisis a movement toward and away from the operative site OS. Both of thesemovements J1 and J2 are controlled by cabling in bundle 21 in order toplace the distal end of the guide tube 17 at the operative site. Theoperative site is defined as the general area in proximity to wheremovement of the tool 18 occurs, usually in the viewing area of theendoscope and away from the incision.

FIG. 8 also shows a coupler 230 pivotally coupled from a base piece 234by means of a pivot pin 232. The coupler 230 is for engaging with andsupporting the proximal end of the instrument insert 16.

Reference is now made to FIGS. 8A, 8B and 8C which are perspective viewsof a preferred clamping arrangement which allows a limited amount ofpivoting of the mounting bracket 25 (which supports instrument 14). Themounting bracket 25 includes a securing knob 450 that clamps themounting bracket 25 to a base 452. The mounting bracket is basically twopieces 455 and 457. A bottom piece 457 is adapted to receive the upperarm of rigid supporting rod 19 (see FIG. 8B) and is secured thereto by abolt 458. A top piece 455 is pivotably adjustable relative to the bottompiece 457 by means of slots 460 that engage with bolts 462. When bolts462 are loosened, the top piece 455 may be rotated relative to thebottom piece 457 so that the instrument 14 may be held in differentpositions. The bolts 462 may then be tightened when the instrument 14 isin a desired angular position.

An adjustable bracket 25 and support post 19 may be provided at eachside of the table for mounting a surgical instrument 14 on both the leftand the right sides of the table. Depending upon the particular surgicalprocedure, it may be desirable to orient a pair of guide tubes on theleft and right sides in different arrangements. In the arrangement ofFIG. 1, the guide tubes 17, 17 are arranged so that the respective tools18, 18 face each other. However, for other procedures it may bedesirable to dispose the guides in different positions, allowed by theadjustability of brackets 25, 25 on their respective support posts 19,19.

FIG. 8D shows a template 470 useful in a preferred procedure forpositioning the guide tube. In this procedure, when the support post 19is initially positioned, the mounting bracket 25 holds the template 470(rather than the instrument 14). The template 470 has a right angle arm472 with a locating ball 474 at the end thereof. The arm 472 extends adistance that is substantially the same as the lateral displacement ofthe guide tube 200 from pivot point 205 above the incision point 207 inFIG. 2C (see also the trocar 487 at the incision point 485 in FIG. 2B).The mounting bracket 25 is adjusted on the support post 19 so that theball 474 coincides with the intended incision point of the patient.Thereafter, the template is removed and when the instrument 14 is thenclamped to the mounting bracket, the guide tube 17 will be in the properposition vis-à-vis the patient's incision. Thus, the template 470 isused to essentially position the bracket 25 where it is desired to belocated with the ball 474 coinciding with the incision point. Once thetemplate is removed and the instrument is secured, the guide tube 17will be in the proper position relative to the incision.

In connection with the operation of the present system, once the patientis on the table, the drive unit 8 is clamped to the table. It's positioncan be adjusted along the table by means of the attaching member 212.The lower arm 19A of the rigid support rod 19 is secured to the table bythe bracket 216. The surgeon determines where the incision is to bemade. The mounting bracket on the rigid rod 19 is adjusted and thetemplate 470 is secured to the clamp 25. The ball 474 on the template islined up with the incision so as to position the securing rod 19 andclamp 25 in the proper position. At that time the rigid rod 19 and thesecuring clamp 25 are fixed in position. Then the template is removedand the instrument 14 is positioned on the clamp 25. The incision hasbeen made and the guide tube 17 is inserted through the incision intothe patient and the instrument 14 is secured at the fixed position ofmounting bracket 25.

With regard to the incision point, reference is made to FIG. 2B whichshows the incision point along the dashed line 485. Also shown at thatpoint is the cannula 487. In some surgical procedures it is common touse a cannula in combination with a trocar that may be used to piercethe skin at the incision. The guide tube 17 may then be inserted throughthe flexible cannula so that the tool is at the operative site. Thecannula typically has a port at which a gas such as carbon dioxideenters for insufflating the patient, and a switch that can be actuatedto desufflate. The cannula may typically include a valve mechanism forpreventing the escape of the gas.

C2—Slave Cabling and Decoupling (FIGS. 8E-8L)

FIG. 8E illustrates a mechanical cabling sequence at the slave stationfrom the drive unit 8, through adaptor 15 and insert 16, to the tool 18.Reference will again be made to FIG. 8E after a description of furtherdetails of the slave station.

In the present embodiment the cable conduits 21 and 22 are detachablefrom the drive unit 8. This is illustrated in FIG. 8F wherein the driveunit includes separable housing sections 855 and 856. The instrument 14along with the attached cable conduits 21 and 22 and housing section 856are, as a unit, of relatively light weight and easily maneuverable(portable) to enable insertion of the instrument 14 into the patientprior to attachment to the bracket 25 on support post 19.

FIG. 8F is an exploded perspective view of the cable drive mechanism andinstrument illustrating the de-coupling concepts of the presentembodiment at the slave station S. A section of the surgical tabletop Twhich supports the rigid post 19 is shown. The drive unit 8 is supportedfrom the side of the tabletop by an L-shaped brace 210 that carries anattaching member 212. The brace 210 is suitably secured to the table T.The drive unit 8 is secured to the attaching member 212 by means of aclamp 214. Similarly, the rigid support rod 19 is secured to theattaching member 212 by means of another clamping mechanism 216.

Also in FIG. 8F the instrument 14 is shown detached from (or not yetattached to) support post 19 at bracket 25. The instrument 14 along withcables 21 and 22 and lightweight housing section 856 provide arelatively small and lightweight decoupleable slave unit that is readilymanually engageable (insertable) into the patient at the guide tube 17.

After insertion, the instrument assembly, with attached cables 21, 22and housing 856, is attached to the support post 19 by means of the knob26 engaging a threaded hole in base 452 of adapter 15. At the other endof the support post 19, bracket 216 has a knob 213 that is tightenedwhen the support rod 19 is in the desired position. The support rod 19,at its vertical arm 19A, essentially moves up and down through the clamp216. Similarly, the mounting bracket 25 can move along the horizontalarm 19B of the support rod to be secured at different positionstherealong. A further clamp 214 enables the drive unit 8 to be moved todifferent positions along the attaching member 212.

FIG. 8F also shows the coupler 230 which is pivotally coupled from basepiece 234 by means of the pivot pin 232. The coupler 230 is for engagingwith and supporting the proximal end of the instrument insert 16.

Reference is now made to FIG. 8G which illustrates the mechanicalcabling sequence at the slave station. The cabling extends from a motor800 (of the drive unit 8), via adaptor 15, and via the instrument insert16 to the tool 18. The adapter 15 and insert 16 are intercoupled bytheir associated interlocking wheels 324 and 334. Cables 606 and 607,which in reality, are a single-looped cable, extend between theinterlocking wheel 334 and the tool 18. These cables 606, 607 are usedfor pivoting the wrist-joint mechanism (at the tool 18), in thedirection of arrow J5 illustrated in FIG. 8G.

FIG. 8G also illustrates an idler pulley 344 on the insert 16, as wellas a pair of pulleys 317 associated with the wheel 324 on the adapter15. Cabling 315 extends from interlocking wheel 324 about the pulleys317, about an idler pulley 318 and through sheathing 319 to conduit turnbuckles 892. The cables 323 extending from the turn buckles 892 arewrapped about a coupler spindle 860. Associated with the coupler spindle860 is a coupler disk 862 secured to an output shaft of one of themotors 800 of drive unit 8.

Reference is now made to further cross-sectional views illustrated inFIGS. 8H-8L. FIG. 8H is a partially broken away front-elevational viewas taken along line 8H—8H of FIG. 8F. FIGS. 8I and 8J arecross-sectional views taken respectively along lines 8I—8I and 8J—8J ofFIG. 8H. FIG. 8K is a cross-sectional side view taken along line 8K—8Kof FIG. 8H. Lastly, FIG. 8L is a cross-sectional view as taken alongline 8L—8L of FIG. 8K.

These cross-sectional views illustrate a series of seven motors 800, onefor each of an associated mechanical cabling assembly. In, FIG. 8K,there is illustrated one of the motors 800 with its output shaft 865extending therefrom. The motor 800 is secured to a housing wall 866(also shown in FIG. 8F). FIG. 8K also shows the angle iron 868 that isused to support the housing section 855 from the bracket 214 (see FIG.8F).

A coupler disk 862 is illustrated in FIGS. 8J and 8K, secured to theshaft 865 by a set screw 869. The coupler disk 862 also supports aregistration pin 871 that is adapted to be received in slots 873 of thecoupler spindle 860. FIGS. 8K and 8L illustrate the pin 871 in one ofthe slots 873. The registration pin 871 is biased outwardly from thecoupler disk by means of a coil spring 874.

The first housing section 855 also carries oppositely disposed thumbscrews 875 (see FIG. 8H). These may be threaded through flanges 876 asillustrated in FIG. 8J. When loosened, these set screws enable thesecond housing section 856 to engage with the first housing section 855.For this purpose, there is provided a slot 878 illustrated in FIG. 8F.Once the second housing section 856 is engaged with the first housingsection 855, then the thumb screws 875 may be tightened to hold the twohousing sections together, at the same time facilitating engagementbetween the coupler disks 862 and the coupler spindles 860.

The cross-sectional view of FIG. 8K shows that at the end of couplerdisk 862 where it is adapted to engage with the coupler spindle 860, thecoupler disk is tapered as illustrated at 879. This facilitatesengagement between the coupler disk and the coupler spindle.

As illustrated in FIG. 8F, the two housing sections 855 and 856 areseparable from each other so that the relatively compact slave unit canbe engaged and disengaged from the motor array, particularly from thefirst housing section 855 that contains the motors 800. The firsthousing section 855, as described previously, contains the motors 800and their corresponding coupler disks 862. In FIG. 8F, the secondhousing section 856 primarily accommodates and supports the couplerspindles 860 and the cabling extending from each of the spindles to thecable bundles 21 and 22 depicted in FIG. 8F.

FIGS. 8J and 8K illustrate one of the coupler spindles 860 supportedwithin a pair of bearings 881. The cable associated with the couplerspindle is secured to the coupler spindle by means of a cable clampscrew 883. FIGS. 8J and 8K illustrate the cable extending about thecoupler spindle, and secured by the cable clamp screw 883. Theparticular cable illustrated in FIGS. 8J about spindle 860 is identifiedas cable D.

In FIGS. 8H-8K, the cabling is identified by cables A-G. This representsseven separate cables that are illustrated, for example, in FIG. 8H asextending into the second housing section 856 with a flexible boot 885(see the top of FIGS. 8H and 8K) extending thereabout.

At the top of the second housing section 856 there is provided a conduitstop or retainer 888 that is secured in place at the top of the housingsection in an appropriate manner. The conduit retainer 888 has throughslots 890, one for accommodating each of the cables A-G (see FIG. 81).Refer in particular to FIGS. 8H and 8K illustrating the cables A-Gextending through the retainer 888 in the slots thereof. Each of thecables may also be provided with a turnbuckle 892 that is useful intensioning the cables. Each turnbuckle 892 screws into an accommodatingthreaded passage in the retainer 888, as illustrated in FIG. 8K.

In FIG. 8H the coupler spindles are all disposed in a linear array. Toproperly accommodate the cabling, the spindles are of varying diameter,commencing at the top of the second housing section 856 with thesmallest diameter spindle and progressing in slightly larger diameterspindles down to the bottom of the second housing section 856 wherethere is disposed the largest diameter coupler spindle.

The detachability of the two housing sections 855 and 856 enables thecleaning of certain components which are disposed above the plane of theoperating table, here referred to as the sterile field. Morespecifically, the detachable housing 856 with attached cables 21 and 22and instrument 14, needs to be sterilized after use, except for theinstrument insert 16 which is an integral disposal unit. Thesterilization of the designated components may include a mechanicalcleaning with brushes or the like in a sink, followed by placement in atray and autoclave in which the components are subjected to superheatedsteam to sterilize the same. In this manner, the adapter 15 is reusable.Also, the engagement between the adapter 15 and insert 16 is such thatthe disposable insert element may have holes, which are relatively hardto clean, whereas the recleanable adapter element has a minimum numberof corresponding projections, which are relatively easier to clean thanthe holes. By disposable, it is meant that the unit, here the insert 16,is intended for a single use as sold in the marketplace. The disposableinsert interfaces with an adapter 15 which is intended to be recleaned(sterilized) between repeated uses. Preferably, the disposable unit,here the insert 16, can be made of relatively lower cost polymers andmaterials which, for example, can be molded by low-cost injectionmolding. In addition, the disposable instrument insert 16 is designed torequire a relatively minimal effort by the operator or other assistantwho is required to attach the insert to the adapter 15. Morespecifically, the operator is not required to rethread any of themultiple mechanical cabling assemblies.

C3—Slave Instrument Assembly (FIGS. 9-16)

Further details of the detachable and portable slave unit are shown inFIGS. 9-16. For example, FIG. 11 shows the carriage 226 which extendsfrom the mounting bracket 25 on support post 19. Below carriage 226, abase piece 234 is supported from the carriage 226 by a rectangular post228. The post 228 supports the entire instrument assembly, including theadaptor 15 and the instrument insert 16 once engaged.

As indicated previously, a support yoke 220 is supported in a fixedposition from the mounting bracket 25 via base 452. Cabling 21 extendsinto the support yoke 220. The support yoke 220 may be considered ashaving an upper leg 236 and a lower leg 238 (see FIG. 12). In theopening 239 between these legs 236, 238 there is arranged the pivotpiece 222 with its attached base 240. Below the base 240 and supportedby the pivot pin 225 is a circular disc 242 that is stationary relativeto the yoke legs 236, 238. A bearing 235 in leg 236, a bearing 237 inleg 238, and a bearing 233 in disc 242, allow rotation of these membersrelative to the pivot pin 225.

Disposed within a recess in the support yoke 220, as illustrated in FIG.13, is a capstan 244 about which cables 245 and 246 extend and arecoupled to opposite sides of the arcuate segment 248 of pivot piece 222.The ends of cables 245 and 246 are secured in holes at opposite sides ofarcuate segment 248. The cables 245 and 246 operate in conjunction witheach other. At their other ends, these cables connect to a motor.Depending upon the direction of rotation of the motor, either cable 245or cable 246 will be pulled, causing the pivot price 232 to rotate in adirection indicated by J1.

The base 240 of pivot piece 222 also has at one end thereof an end piece241 into which are partially supported the ends of rails 224 (see FIG.13). The other ends of the rails are supported by an end piece 251,which also has cabling 257, 258 for the carriage 226 extendingtherethrough, such as illustrated in FIG. 14. A capstan 253 is supportedfrom a lower surface of the base 240. Another capstan 256 is supportedwithin the support yoke 220. The cables 257 and 258 extend about thecapstan 256, about disc 242 (which may be grooved to receive thecables), to the carriage 226, and from there about another capstan 260disposed within end member 262 (see FIG. 11). End member 262 supportsthe other ends of the rails 224, upon which the carriage 226transitions. The ends of the cables 257 and 258 are securedappropriately within the carriage. FIG. 11 illustrates by the arrow 227the forward and backward motion of the carriage 226, and thus of theattached actuator 15 toward and away from the operative site.

Now, reference is made to FIG. 15 illustrating a portion of the slaveunit with the instrument insert 16 partially removed and rotated fromthe base piece 234. FIG. 15 shows a portion of the carriage mechanism,including the carriage 226 supported on rails 224. As indicatedpreviously, below the carriage 226 there is a support post 228 thatsupports the base piece 234. It is at the base piece 234, that cabling22 from the drive unit 8 is received.

Also extending from the base piece 234 is the guide tube 17 of adapter15. The guide tube 17 accommodates, through its center axial passage,the instrument insert 16. Also, supported from the base piece 234, atpivot pin 232, is the adaptor coupler 230. The adaptor coupler 230pivots out of the way so that the instrument insert 16 can be insertedinto the adaptor 15. FIG. 15 shows the instrument insert 16 partiallywithdrawn from the adaptor 15. The pivot pin 232 may be longer than thedistance between the two parallel bars 270 and 272 carried by base piece234, so that the pin not only allows rotation, but can also sliderelative to bars 270 and 272. This permits the coupler 230 to not onlypivot, but also to move laterally to enable better access of theinstrument insert 16 into the base piece 234. The instrument insert 16has a base (coupler) 300 that in essence is a companion coupler to theadapter coupler 230.

With further reference to FIG. 15, the instrument insert 16 is comprisedof a coupler 300 at the proximal end, and at the distal end an elongatedshaft or stem, which in this embodiment has a more rigid proximal stemsection 301 and a flexible distal stem section 302 (see FIG. 15A). Thedistal stem section 302 carries the tool 18 at its distal end. Theinstrument coupler 300 includes one or more wheels 339 which laterallyengage complimentary wheels 329 of the coupler 230 on adaptor 15. Theinstrument coupler 300 also includes an axial wheel 306 at its distalend through which the stem 301 extends, and which also engages a wheelon the adaptor, as to be described below in further detail. The axialengagement wheel 306 is fixed to the more rigid stem section 301, and isused to rotate the tool 18 axially at the distal end of the flexiblestem section 302 (as shown by arrow J4 in FIG. 2B).

The base piece 234 has secured thereto two parallel spaced-apart bars270 and 272. It is between these bars 270 and 272 that is disposed thepivot pin 232. The pivot pin 232 may be supported at either end inbearings in the bars 270 and 272, and as previously mentioned, haslimited sliding capability so as to move the adapter coupler 230 awayfrom base piece 234 to enable insertion of the instrument insert 16. Aleg 275 is secured to the pivot pin 232. The leg 275 extends from thecoupler 230 and provides for pivoting of coupler 230 with respect tobase piece 234. Thus, the combination of pivot pin 232 and the leg 275permits a free rotation of the coupler 230 from a position where it isclear to insert the instrument insert 16 to a position where the coupler230 intercouples with the base 300 of the instrument insert 16. Asdepicted in FIG. 15, the bars 270 and 272 also accommodate therethroughcabling from cable bundles 271.

The base piece 234 also rotatably supports the rigid tube 17(illustrated by arrow J3 in FIG. 2B). As indicated previously, it is theconnection to the carriage 226 via post 228 that enables the actuator 15to move toward and away from the operative site. The rotation of thetube 17 is carried out by rotation of pulley 277 (see FIG. 15). A pairof cables from the bundle 271 extend about the pulley 277 and can rotatethe pulley in either direction depending upon which cable is activated.To carry out this action, the tube 17 is actually supported on bearingswithin the base piece 234. Also, the proximal end of the tube 17 isfixed to the pulley 277 so that the guide tube 17 rotates with thepulley 277.

Also supported from the very proximal end of the tube 17, is a secondpulley 279 that is supported for rotation about the actuator tube 17.For this purpose a bearing is disposed between the pulley 279 and theactuator tube. The pulley 279 is operated from another pair of cables inthe bundle 271 that operate in the same manner. The cabling is such thattwo cables couple to the pulley 279 for operation of the pulley inopposite directions. Also, as depicted in FIG. 15, the pulley 279 has adetent at 280 that is adapted to mate with a tab 281 on the axial wheel306 of instrument coupler 300. Thus, as the pulley 279 is rotated, thiscauses a rotation of the axial wheel 306 and a corresponding rotation offlexible and rigid sections 301, 302 of the instrument insert 16,including the tool 18.

Again referring to FIG. 15, a block 310 is secured to one side of thecoupler 230. The block 310 is next to the leg 275 and contains a seriesof small, preferably plastic, pulleys that accommodate cabling 315.These cables extend to other pulleys 317 disposed along the length ofthe coupler 230. Refer also to the cabling diagram of FIG. 8E.

In this embodiment, the coupler 230 includes wheels 320, 322 and 324.Each of these wheels is provided with a center pivot 325 to enablerotation of the wheels in the coupler 230. The knob 327 is used tosecure together the adapter coupler 230 and the base coupler 300 of theinstrument insert 16.

For the three wheels, 320, 322 and 324, there are six correspondingpulleys 317, two pulleys being associated with each wheel (see FIGS. 8Eand 11B). Similarly, there are six pulleys in the block 310. Thus, forcabling bundle 315 there are six separate cable conduits for the sixseparate cables that couple to the wheels 320, 322 and 324. Two cablesconnect to each wheel for controlling respective opposite directions ofrotation thereof.

Each of the wheels 320, 322 and 324 have a half-moon portion with a flatside 329. Similarly, the instrument base 300 has companion wheels 330,332 and 334 with complimentary half-moon construction for engagementwith the wheels 320, 322 and 324. The wheel 320 controls one of the jawsof the tool 18 (motion J6 in FIG. 2B). The wheel 324 controls the otherjaw of the tool 18 (motion J7 in FIG. 2B). The middle wheel 322 controlsthe wrist pivoting of the tool 18 (motion J5 in FIG. 2B). Also refer toFIG. 8E showing cabling for controlling tool movement.

The coupler 300 of insert 16 has three wheels 330, 332 and 334, eachwith a pivot pin 331, and which mate with the corresponding wheels 320,322 and 324, respectively of the adaptor coupler. In FIG. 15 theinstrument base piece 300 is shown rotated from its normal position forproper viewing of the wheels. Normally, it is rotated through 180° sothat the half-moon wheels 330, 332 and 334 engage with the correspondingcoupler wheels 320, 322 and 324. Also illustrated in FIG. 15 arecapstans or idler pulleys 340, 342 and 344 associated, respectively,with wheels 330, 332 and 334.

As shown in FIG. 15A, each wheel of the instrument coupler 300 has twocables 376 that are affixed to the wheel (e.g., wheel 334 in FIG. 8E)and wrapped about opposite sides at its base. The lower cable rides overone of the idler pulleys or capstans (e.g., capstan 34 in FIG. 8E),which routes the cables toward the center of the instrument stem 301. Itis desirable to maintain the cables near the center of the instrumentstem. The closer the cables are to the central axis of the stem, theless disturbance motion on the cables when the insert stem is rotated.The cables may then be routed through fixed-length plastic tubes thatare affixed to the proximal end of the stem section 301 and the distalend of the stem section 302. The tubes maintain constant length pathwaysfor the cables as they move within the instrument stem.

The instrument coupler 300 is also provided with a registration slot 350at its distal end. The slot 350 engages with a registration pin 352supported between the bars 270 and 272 of base piece 234. The coupler300 is also provided with a clamping slot 355 on its proximal end foraccommodating the threaded portion of the clamping knob 327 (on adaptercoupler 230). The knob 327 affirmatively engages and interconnects thecouplers 230 and 300.

In operation, once the surgeon has selected a particular instrumentinsert 16, it is inserted into the adapter 15. The proximal stem 301,having the distal stem 302 and the tool 18 at the distal end, extendthrough the adapter guide tube 17. FIG. 8 shows the tool 18 extendingout of the guide tube 17 when the surgical instrument 16 is fullyinserted into the adaptor 15. When it is fully inserted, the tab 281 onthe axial wheel 306 engages with the mating detent 280 in pulley 279.Also, the registration slot 350 engages with the registration pin 352.Then the coupler 230 is pivoted over the base 300 of the instrumentinsert 16. As this pivoting occurs, the respective wheels of the coupler230 and the coupler 300 interengage so that drive can occur from thecoupler 230 to the insert 16. The knob 327 is secured down so that thetwo couplers 230 and 300 remain in fixed relative positions.

Reference is also now made to detailed cross-sectional views of FIGS.11A, 11B and 11C. FIG. 11A is a cross sectional view taken along line11A—11A of FIG. 11. FIG. 11B is a cross-sectional view taken along line11B—11B of FIG. 11A. FIG. 11C is a further cross-sectional view takenthrough FIG. 11A along line 11C—11C.

The base piece 234 of adapter 15 rotatably supports the guide tube 17,allowing rotation J3 shown in FIG. 2B. As noted in FIG. 11A, there are apair of bearings 360 disposed at each end within the axial passage 362in the base piece 234. The rotation of the guide tube 17 is carried outby rotation of the first pulley 277. In FIG. 11A there is a set screw364 that secures the pulley 277 to the guide tube 17. Nylon spacers 366separate various components, such as the base piece 234 and the pulley277, the two pulleys 277 and 279, and base 300 and wheel 306.

A nylon bearing 368 is also provided between the second pulley 279 andthe guide tube 17. FIG. 11A also shows the proximal stem section 301 ofthe insert 16 inside of the guide tube 17. A nylon bearing 370 issupported within the front block 372 of the insert 16.

In FIG. 11A, the second pulley 279 is supported from the proximal end ofthe tube 17. The bearing 368 is disposed between the pulley 279 and thetube 17. The pulley 279 has a detent 280 that is adapted to mate with atab 281 on the axial wheel 306. Thus, when the pulley 279 is rotated bycabling 271 (see FIG. 11C), this causes a rotation of the axial wheel306, and a corresponding rotation (motion J4 in FIG. 2B) of the sections301, 302 of the instrument insert 16, including the tool 18. The veryproximal end of the section 301 is illustrated in FIG. 11A as beingrotatable relative to the bearing 370.

FIG. 11A also shows the intercoupling of the instrument and adaptercouplers 230 and 300. Here wheel 324 is shown interlocked with wheel334. FIGS. 11A and 11C also show cabling at 376. This cabling includessix separate cables that extend through the length of the stem 301, 302of the instrument. The cabling is illustrated connecting about an idlerpulley 344. The cabling associated with wheel 334 is secured by thecable clamping screw 378. For further details of the cabling, refer toFIG. 8E.

FIG. 11B is a cross-sectional view taken along 11B—11B of FIG. 11A whichagain shows the cooperating wheels 324 and 334. Also illustrated is acable clamping set screw 380 that is used to secure the cabling 376 towheel 324. A cable guide rail 382 is attached and forms part of the baseof the adapter coupler 230. The cable guide rail 382 contains six idlerpulleys 317, one of which is illustrated in FIG. 11B. It is noted thatcabling 376 extends about this pulley to the cable idler block 310 whereconduits 315 are coupled. The cable guide idler block 310 includes aseries of six idler pulleys shown in dotted outline in FIG. 11B at 386.

FIG. 11C is a cross-sectional view taken along line 11C—11C of FIG. 11A,which shows further details at the pulley 279. Also illustrated is post228 supporting the base piece 234 of the instrument insert, and cabling376 extending through the instrument.

FIGS. 16A and 16B illustrate the construction of one form of a tool.FIG. 16A is a perspective view and FIG. 16B is an exploded view. Thetool 18 is comprised of four members including a base 600, link 601,upper grip or jaw 602 and lower grip or jaw 603. The base 600 is affixedto the flexible stem section 302 (see FIG. 15A). The flexible stem maybe constructed of a ribbed plastic. This flexible section is used sothat the instrument will readily bend through the curved part of theguide tube 17.

The link 601 is rotatably connected to the base 600 about axis 604. FIG.16B illustrates a pivot pin 620 at axis 604. The upper and lower jaws602 and 603 are rotatably connected by pivot pin 624 to the link 601about axis 605, where axis 605 is essentially perpendicular to axis 604.

Six cables 606-611 actuate the four members 600-603 of the tool. Cable606 travels through the insert stem (section 302) and through a hole inthe base 600, wraps around curved surface 626 on link 601, and thenattaches on link 601 at 630. Tension on cable 606 rotates the link 601,and attached upper and lower grips 602 and 603, about axis 604 (motionJ5 in FIG. 2B). Cable 607 provides the opposing action to cable 606, andgoes through the same routing pathway, but on the opposite sides of theinsert. Cable 607 may also attach to link 601 generally at 630.

Cables 608 and 610 also travel through the stem 301, 302 and thoughholes in the base 600. The cables 608 and 610 then pass between twofixed posts 612. These posts constrain the cables to pass substantiallythrough the axis 604, which defines rotation of the link 601. Thisconstruction essentially allows free rotation of the link 601 withminimal length changes in cables 608-611. In other words, the cables608-611, which actuate the jaws 602 and 603, are essentially decoupledfrom the motion of link 601. Cables 608 and 610 pass over roundedsections and terminate on jaws 602 and 603, respectively. Tension oncables 608 and 610 rotate jaws 602 and 603 counter-clockwise about axis605. Finally, as shown in FIG. 16B, the cables 609 and 611 pass throughthe same routing pathway as cables 608 and 610, but on the opposite sideof the instrument. These cables 609 and 611 provide the clockwise motionto jaws 602 and 603, respectively. At the jaws 602 and 603, as depictedin FIG. 16B, the ends of cables 608-611 may be secured at 635, forexample by the use of an adhesive such as epoxy glue, or the cablescould be crimped to the jaws.

To review the allowed movements of the various components of the slaveunit, the instrument insert 16 slides through the guide tube 17 ofadaptor 15, and laterally engages the adaptor coupler 230. The adaptorcoupler 230 is pivotally mounted to the base piece 234. The base piece234 rotationally mounts the guide tube 17 (motion J3). The base piece234 is affixed to the linear slider or carriage assembly (motion J2).The carriage assembly in turn is pivotally mounted at the pivot 225(motion J1).

Reference is now made to FIGS. 16C and 16D. FIG. 16C is a fragmentaryperspective view of an alternate set of jaws, referred to as needledrivers. FIG. 16D is a side elevation view of the needle drivers. Thisembodiment employs an over-center camming arrangement so that the jaw isnot only closed, but also at a forced closure.

In FIGS. 16C and 16D, similar reference characters are employed withrespect to the embodiment of FIGS. 16A and 16B. Thus, there is provideda base 600, a link 601, an upper jaw 650 and a lower jaw 652. The base600 is affixed to the flexible stem section 302. Cabling 608-611 operatethe end jaws. Linkages 654 and 656 provide the over-center cammingoperation.

The two embodiments of FIGS. 16A-16D employ a fixed wrist pivot. Analternate construction is illustrated in FIGS. 16E-16H in which there isprovided, in place of a wrist pivot, a flexible or bending section. InFIGS. 16E-16H, similar reference characters are used for many of theparts, as they correspond to elements found in FIGS. 16A-16D.

In the embodiment of FIGS. 16E-16H, the tool 18 is comprised of an uppergrip or jaw 602 and a lower grip or jaw 603, supported from a link 601.Each of the jaws 602, 603, as well as the link 601, may be constructedof metal, or alternatively, the link 601 may be constructed of a hardplastic. The link 601 is engaged with the distal end of the flexiblestem section 302. In this regard reference may also be made to FIG. 15Athat shows the ribbed, plastic construction of the flexible stem section302. FIG. 16E shows only the very distal end of the stem section 302,terminating in a bending or flexing section 660. The flexible stemsection 302 is constructed so as to be flexible and thus has asubstantial length of a ribbed surface as illustrated in FIG. 15A. Also,at the flexible section 660, flexibility and bending is enhanced bymeans of diametrically-disposed slots 662 that define therebetween ribs664. The flexible section 660 also has a longitudinally extending wall665, through which cabling extends, particularly for operation of thetool jaws. The very distal end of the bending section 660 terminateswith an opening 666 for receiving the end 668 of the link 601. Thecabling 608-611 is preferably at the center of the flex section at wall665 so as to effectively decouple flex or bending motions from toolmotions.

Regarding the operation of the tool, reference is made to the cables608,609,610, and 611. All of these extend through the flexible stemsection and also through the wall 665 such as illustrated in FIG. 16G.The cables extend to the respective jaws 602,603 for controllingoperation thereof in a manner similar to that described previously inconnection with FIGS. 16A-16D. FIGS. 16E-16H also illustrate the cables606 and 607 which couple through the bending section 660 and terminateat ball ends 606A and 607A, respectively. Again, refer to FIG. 16G thatshows these cables. FIGS. 16F and 16H also show the cables 606,607 withthe ball ends 606A, 607A, respectively. These ball ends are adapted tourge against the very end of the bendable section in opening 666. Whenthese cables are pulled individually, they can cause a bending of thewrist at the bending or flexing section 660. FIG. 16H illustrates thecable 607 having been pulled in the direction of arrow 670 so as to flexthe section 660 in the manner illustrated in FIG. 16H. Pulling on theother cable 606 causes a bending in the opposite direction.

By virtue of the slots 662 forming the ribs 664, there is provided astructure that bends quite readily, essentially bending the wall 665 bycompressing at the slots such as in the manner illustrated in FIG. 16H.This construction eliminates the need for a wrist pin or hinge.

The embodiment illustrated in FIG. 16F has a separate link 601. However,in an alternate embodiment, this link 601 may be fabricated integrallywith, and as part of, the bending section 660. For this purpose the link601 would then be constructed of a relatively hard plastic rather thanthe metal link as illustrated in FIG. 16F and would be integral withsection 660.

In another embodiment, the bending or flexing section 660 can beconstructed so as to have orthogonal bending by using four cablesseparated at 90° intervals and by providing a center support with ribsand slots about the entire periphery. This embodiment is shown in FIGS.16I-16K. The bending section 613 is at the end of flexible stem section302. The cables 608, 609, 610 and 611 are for actuation of the jaws 602and 603 in the same manner as for earlier embodiments. The link 601couples the bending section 613 to the jaws 602 and 603.

The bending section has a center support wall 614 supporting ribs 618separated by slots 619. This version enables bending in orthogonaldirections by means of four cables 606,607,616 and 617, instead of thesingle degree-of-freedom of FIG. 16E. The operation of cables 606 and607 provides flexing in one degree-of-freedom, while an addeddegree-of-freedom is provided by operation of cables 616 and 617.

Mention has also been made of various forms of tools that can be used.The tool may comprise a variety of articulated tools such as: jaws,scissors, graspers, needle holders, micro dissectors, staple appliers,tackers, suction irrigation tools and clip appliers. In addition, thetool may comprise a non-articulated instrument such as: a cutting blade,probe, irrigator, catheter or suction orifice.

C4—Slave Drive Unit (FIGS. 17-17A)

Reference is now made to the perspective view of the drive unit 8,previously illustrated in FIG. 8. FIG. 17 illustrates the drive unit 8with the cover removed. The drive unit is adjustably positionable alongrail 212 by an angle brace 210 that is attached to the operating table.Within the drive unit 8 are seven separate motors 800, corresponding tothe seven separate controls at the slave station, and more particularly,to motions J1-J7 previously described in reference to FIG. 2B.

The drive unit includes a support plate 805 to which there is secured aholder 808 for receiving and clamping the cabling conduits 835. Themotors 800 are each supported from the support plate 805. FIG. 17 alsoillustrates the electrical interface at 810, with one or more electricalconnectors 812.

Regarding support for the motors 800 there is provided, associated witheach motor, a pair of opposed adjusting slots 814 and adjusting screws815. This permits a certain degree of positional adjustment of themotors, relative to their associated idler pulleys 820. The seven idlerpulleys are supported for rotation by means of a support bar 825. FIG.17 also shows the cabling coming 830 from each of the idler pulleys.With seven motors, and two cables coming off of each motor for oppositedirection control, there are a total of fourteen separate cablesconduits at the bundle 835. The cables move within the conduits in aknown manner. The conduits themselves are fixedly supported and extendfrom the holder 808 to the adapter 15. Again, reference may be made toFIG. 8 showing the conduit bundles at 21 and 22.

The seven motors in this embodiment control (1) one jaw of the tool J6,(2) the pivoting of the wrist at the tool J5, (3) the other jaw of thetool J7, (4) rotation of the insert J4, (5) rotation of the adaptor J3,(6) linear carriage motion J2 and (7) pivoting of the adaptor J1. Ofcourse, fewer or lesser numbers of motors may be provided in otherembodiments and the sequence of the controls may be different.

FIG. 17A illustrates another aspect of the invention—a feedback systemthat feeds force information from the slave station back to the masterstation where the surgeon is manipulating the input device. For example,if the surgeon is moving his arm to the left and this causes someresistance at the slave station, the resistance is detected at the slavestation and coupled back to one of the motors at the master station todrive the input device, such as the hand assembly illustrated herein,back in the opposite direction. This provides an increased resistance tothe surgeon's movements which occurs substantially instantaneously.

FIG. 17A illustrates schematically a load cell 840 that is adapted tosense cable tension. FIG. 17A shows one of the pulleys 842 associatedwith one of the motors 800, and cables 845 and 847 disposed about asensing pulley 850. The sensing pulley 850 is coupled to thepiezoelectric load cell 840. The load cell 840 may be disposed in aWheatstone bridge arrangement.

Thus, if one of the motors is operating under tension, this is sensed bythe load cell 840 and an electrical signal is coupled from the slavestation, by way of the controller 9, to the master station to controlone of the master station motors. When tension is sensed, this drivesthe master station motor in the opposite direction (to the direction ofmovement of the surgeon) to indicate to the surgeon that a barrier orsome other obstacle has been encountered by the element of the slaveunit being driven by the surgeon's movements.

The cabling scheme is important as it permits the motors to be locatedin a position remote from the adaptor and insert. Furthermore, it doesnot require the motor to be supported on any moving arms or the like.Several prior systems employing motor control have motors supported onmoveable arms. Here the motors are separated from the active instrumentarea (and sterile field) and furthermore are maintained fixed inposition. This is illustrated in FIG. 8E by the motor 800. FIG. 8E alsoillustrates a typical cabling sequence from the motor 800 through to thetool 18. Both ends of cabling 315 are secured to the motor at 842 andthe motor is adapted to rotate either clockwise or counterclockwise, inorder to pull the cabling in either one direction or the other. The pairof cabling operates in unison so that as one cable is pulled inwardlytoward the motor, the other cable pulls outwardly. As illustrated inFIG. 8E, the cables extend over pulley 820 to other pulleys, such as thepair of pulleys 317 and control wheel 324 associated with coupler 230.From there, the mechanical drive is transferred to the control wheel 334of the instrument insert 300, which is coupled to wheel 334 and to theoutput cables 606 and 607 which drive wrist rotation of the tool 18,identified in FIG. 8E by the motion J5.

Another important aspect is the use of inter-mating wheels, such as thewheels 324 and 334 illustrated in FIG. 8E. This permits essentially aphysical interruption of the mechanical cables, but at the same time amechanical drive coupling between the cables. This permits the use of aninstrument insert 16 that is readily engageable with the adaptor, aswell as disengagable from the adaptor 15. This makes the instrumentinsert 16 easily replacable and also, due to the simplicity of theinstrument insert 16, it can be made disposable. Refer again to FIG. 15Awhich shows the complete instrument insert and its relatively simpleconstruction, but which still provides an effective coupling between thedrive motor and the tool.

C5—Slave Guide Tube (FIGS. 19-19D)

Reference is now made to FIG. 19, a schematic diagram illustratingdifferent placements of the guide tube 17. FIG. 19A illustrates left andright guide tubes substantially in the same position as illustrated inFIG. 1. For some surgical procedures, it may be advantageous to orientthe tubes so that the curvatures are in the same direction. FIG. 19Bshows the ends of the tubes pointing to the right, while FIG. 19C showsthe ends of the tubes pointing to the left. Lastly, in FIG. 19D the endsof the tubes are shown converging but in a downwardly directed position.Regarding the different placements shown in FIG. 19, the adjustableclamp 25, illustrated in FIGS. 8A-8C may be useful, as this providessome added level of flexibility in supporting the positioning of theguide tubes on both the left and right side.

C6—Slave Motor Control (FIGS. 20-28)

FIGS. 20 and 21 are block diagrams of the motor control system of thepresent embodiment. In the system of FIG. 1, there are two instrumentssupported on either side of the operating table. Thus, there are inactuality two separate drive units 8. One of these is considered a lefthand (LH) station and the other is considered a right hand (RH) station.Similarly, at the master station, on either side of the chair, asdepicted in FIG. 1, there are left hand and right hand master stationassemblies. Accordingly, there are a total of 28 (7×4) separate actionsthat are either sensed or controlled. This relates to seven separatedegrees-of-motion at both the master and slave, as well as at left handand right stations. In other embodiments there may be only a singlestation, such as either a left hand station or a right hand station.Also, other embodiments may employ fewer or greater numbers ofdegrees-of-motion as identified herein.

Regarding the master station side, there is at least one positionencoder associated with each of degree-of-motion or degree-of-freedom.Also, as previously described, some of the described motions of theactive joints have a combination of motor and encoder on a common shaft.With regard to the master station, all of the rotations represented byJ1, J2 and J3 (see FIG. 2A) have associated therewith, not only encodersbut also individual motors. At the hand assembly previously described,there are only encoders. However, the block diagram system of FIGS. 20and 21 illustrates a combination with motor and encoder. If a motor isnot used at a master station, then only the encoder signal is coupled tothe system.

FIGS. 20 and 21 illustrate a multi-axis, high performance motor controlsystem which may support anywhere from 8 to 64 axes, simultaneously,using either eight-bit parallel or pulse width modulated (PWM) signals.The motors themselves may be direct current, direct current brushless orstepper motors with a programmable digital filter/commutater. Each motoraccommodates a standard incremental optical encoder.

The block diagram of FIG. 20 represents the basic components of thesystem. This includes a host computer 700, connected by a digital bus702 to an interface board 704. The interface board 704 may be aconventional interface board for coupling signals between the digitalbus and the eight individual module boards 706. The set of module boardsis referred to as the motor control sub unit. Communication cables 708intercouple the interface board 704 to eight separate module boards 706.The host computer 700 may be an Intel microprocessor based personalcomputer (PC) at a control station preferably running a Windows NTprogram communicating with the interface board 704 by way of ahigh-speed PCI bus 702 (5.0 KHz for eight channels to 700 Hz for 64channels).

FIG. 21 shows one of the module boards 706. Each board 706 includes fourmotion control circuits 710. Each of the blocks 710 may be aHewlett-Packard motion control integrated circuit. For example, each ofthese may be an IC identified as HCTL1100. Also depicted in FIG. 21 is apower amplifier sub unit 712. The power amplifier sub unit is based onNational Semiconductor's H-bridge power amplifier integrated circuitsfor providing PWM motor command signals. The power amplifier 712associated with each of the blocks 710 couples to a motor X. Associatedwith motor X is encoder Y. Also note the connection back from eachencoder to the block 710. In FIG. 21, although the connections are notspecifically set forth, it is understood that signals intercouplebetween the block 710 and the interface board 704, as well as via bus702 to the host computer 700.

The motor control system may be implemented for example, in two ways. Ina first method the user utilizes the motor control subunit 706 to effectfour control modes: positional control, proportional velocity control,trapezoidal profile control and integral velocity control. Using any oneof these modes means specifying desired positions or velocities for eachmotor, and the necessary control actions are computed by the motioncontrol IC 710 of the motor control subunit, thereby greatly reducingthe complexity of the control system software. However, in the casewhere none of the on-board control modes are appropriate for theapplication, the user may choose a second method in which a servo motorcontrol software is implemented at the PC control station. Appropriatevoltage signal outputs for each motor are computed by the PC controlstation and sent to the motor control/power amplifier unit (706, 712).Although the computation load is mostly placed on the control station'sCPU in this case, there are available high performance computers andhigh speed PCI buses for data transfer which can accommodate this load.

D. Master—Slave Positioning and Orientation (FIGS. 22-28)

FIG. 22 provides an overview of control algorithm for the presentembodiment. Its primary function is to move the instrument tool 18 insuch a way that the motions of the instrument tool are precisely mappedto that of the surgeon interface device 3 in three dimensional space,thereby creating the feel of the tool being an extension of thesurgeon's own hands. The control algorithm assumes that both thesurgeon's input interface as well as the instrument system always startat predefined positions and orientations, and once the system isstarted, it repeats a series of steps at every sampling period. Thepredefined positions and orientations, relate to the initial positioningof the master and slave stations.

First, the joint sensors (box 435), which are optical encoders in thepresent embodiment, of the surgeon's interface system are read, and viaforward kinematics (box 410) analysis, the current position (see line429) and orientation (see line 427) of the input interface handle aredetermined. The translational motion of the surgeon's hand motion isscaled (box 425), whereas the orientation is not scaled, resulting in adesired position (see line 432) and orientation (see line 434) for theinstrument tool. The results are then inputted into the inversekinematics algorithms (box 415) for the instrument tool, and finally thenecessary joint angles and insertion length of the instrument system aredetermined. The motor command positions are sent to the instrument motorcontroller (box 420) for commending the corresponding motors topositions such that the desired joint angles and insertion length areachieved.

With further reference to FIG. 22, it is noted that there is alsoprovided an initial start position for the input device, indicated atbox 440. The output of box 440 couples to a summation device 430. Theoutput of device 430 couples to scale box 425. The initial handle (orhand assembly) position as indicated previously is established by firstpositioning of the handle at the master station so as to establish aninitial master station handle orientation in three dimensional space.This is compared to the current handle position at device 430. This isthen scaled by box 425 to provide the desired tool position on line 432to the instrument inverse kinematics box 415.

The following is an analysis of the kinematic computations for both box410 and box 415 in FIG. 22.

Kinematic Computations

The present embodiment provides a surgeon with the feel of an instrumentas being an extension of his own hand. The position and orientation ofthe instrument tool is mapped to that of the surgeon input interfacedevice, and this mapping process is referred to as kinematiccomputations. The kinematic calculations can be divided into twosub-processes: forward kinematic computation of the surgeon userinterface device, and inverse kinematic computation of the instrumenttool.

Forward Kinematic Computation

Based on the information provided by the joint angle sensors, which areoptical encoders of the surgeon interface system, the forward kinematiccomputation determines the position and orientation of the handle inthree dimensional space.

1. Position

The position of the surgeon's wrist in three dimensional space isdetermined by simple geometric calculations. Referring to FIG. 23, thex, y, z directional positions of the wrist with respect to the referencecoordinate areX _(p)=(L ₃ sin θ₃ +L ₂ cos θ_(2a))cos θ_(bp) −L ₂Y _(p)=−(L ₃ cos θ₃ +L ₂ sin θ_(2a))−L ₃Z _(p)=(L ₃ sin θ₃ +L ₂ cos θ_(2a))sin θ_(bp)where X_(p), Y_(p), Z_(p) are wrist positions in the x, y, z directions,respectively.

These equations for X_(p), Y_(p), and Z_(p) represent respectivemagnitudes as measured from the initial reference coordination location,which is the location in FIG. 23 when θ₃ and θ_(2a) are both zerodegrees. This corresponds to the position wherein arm L2 is at rightangles to arm L3, i.e., arm L2 is essentially horizontal and arm L3 isessentially vertical. That location is identified in FIG. 23 ascoordinate location P′ where X_(p)=Y_(p)=Z_(p)=0. Deviations from thisreference are calculated to determine the current position P.

The reference coordinates for both the master and the slave areestablished with respect to a base location for each. In FIG. 23 it islocation BM that corresponds structurally to the axis 60A in FIG. 2A. InFIG. 25 it is the location BS that corresponds structurally to the axis225A in FIG. 2B. Because both the master and slave structures havepredefined configurations when they are initialized, the locations ofthe master wrist 60A and the slave pivot 225A are known by the knowndimensions of the respective structures. The predefined configuration ofthe master in the illustrated embodiment, per FIG. 23, relates to knownlengths of arms L2 and L3, corresponding to arm 91 or arm 92, and arm 96respectively. The predefined configuration of the slave is similarlydefined, per FIG. 25, by dimensions of arms L_(s) and L_(b) and byinitializing the slave unit with the guide tube 17 flat in one plane(dimension Y=O) and the arm L_(s) in line with the Z axis.

2. Orientation

The orientation of the surgeon interface handle in three dimensionalspace is determined by a series of coordinate transformations for eachjoint angle. As shown in FIG. 24, the coordinate frame at the wristjoint is rotated with respect to the reference coordinate frame by jointmovements θ_(bp), θ₂, θ₃ and θ_(ax). Specifically, the wrist jointcoordinate frame is rotated (−θ_(bp)) about the y axis, (−θ_(2a)) aboutthe z axis and θ_(ax) about the x axis where θ_(2a) is θ₂−θ₃. Theresulting transformation matrix R_(wh) for the wrist joint coordinateframe with respect to the reference coordinate is then$R_{wh} = \left\lbrack \quad\begin{matrix}R_{wh11} & R_{wh12} & R_{wh13} \\R_{wh21} & R_{wh22} & R_{wh23} \\R_{wh31} & R_{wh32} & R_{wh33}\end{matrix}\quad \right\rbrack$

where R_(wh11)=cos θ_(bp1) cos θ_(2a)

R_(wh12)=cos θ_(bp1) sin θ_(2a) cos θ_(ax)−sin θ_(bp1) sin θ_(ax)

R_(wh13)=−cos θ_(bp1) sin θ_(2a) sin θ_(ax)−sin θ_(bp1) cos θ_(ax)

R_(wh21)=−sin θ_(2a)

R_(wh22=cos θ) _(2a) cos θ_(ax)

R_(wh23)−cos θ_(2a) sin θ_(ax)

R_(wh31)sin θ_(bp1) cos ₇₄ _(2a)

R_(wh32)=sin θ_(bp1) sin θ_(2a) cos θ_(ax)+cos θ_(bp1) sin θ_(ax)

R_(wh33)=−sin θ_(bp1) sin θ_(2a) sin θ_(ax)+cos θ_(bp1) cos θ_(ax)

Similarly, the handle coordinate frame rotates joint angles φ and(−θ_(h)) about the z and y axes with respect to the wrist coordinateframe. The transformation matrix R_(hwh) for handle coordinate framewith respect to the wrist coordinate is then$R_{hwh} = \left\lbrack \quad\begin{matrix}R_{hwh11} & R_{hwh12} & R_{hwh13} \\R_{hwh21} & R_{hwh22} & R_{hwh23} \\R_{hwh31} & R_{hwh32} & R_{hwh33}\end{matrix}\quad \right\rbrack$

where R_(hwh11)=cos φ cos θ_(h)

R_(hwh12)=−sin φ

R_(hwh13)=−cos φ sin θ_(h)

R_(hwh21)=sin φ cos θ_(h)

R_(hwh22)=cos φ

R_(hwh23)=−sin φ sin θ_(h)

R_(hwh31)=sin θ_(h)

R_(hwh32)=0

R_(hwh33)=cos θ_(h)

Therefore, the transformation matrix R_(h) for handle coordinate framewith respect to the reference coordinate is

R_(h)=R_(wh) R_(hwh)

Inverse Kinematic Computation

Once the position and orientation of the surgeon interface handle arecomputed, the instrument tool is to be moved in such a way that theposition of the tool's wrist joint in three dimensional space X_(w),Y_(w), Z_(w) with respect to the insertion point are proportional to theinterface handle's positions by a scaling factor α(X _(w) −X _(w) _(—ref) )=αX _(p)(Y _(w) −Y _(w) _(—ref) )=αY _(p)(Z _(w) −Z _(w) _(—ref) )=αZ _(p)

where X_(w) _(—ref) , Y_(w) _(—ref) , Z_(w) _(—ref) are the initialreference positions of the wrist joint. The orientations could be scaledas well, but in the current embodiment, are kept identical to that ofthe interface handle.

When X_(w) _(—ref) ,=Y_(w) _(—ref) ,=Z_(w) _(—ref) =0 the foregoingequations simplify to:

X_(w)=αX_(p)

Y_(w)=αY_(p)

Z_(w)=αZ_(p)

where (X_(w), Y_(w), Z_(w),), (X_(p), Y_(p), X_(p),) and α are thedesired absolute position of the instrument, current position of theinterface handle and scaling factor, respectively.

1. Position

The next task is to determine the joint angles ω, Ψ and the insertionlength L_(s) of the instrument, as shown in FIG. 25, necessary toachieve the desired positions of the tool's wrist joint. Given Y_(w),the angle ω is${\omega = {{{\arcsin\left( \frac{Y_{w}}{L_{bs}} \right)}\omega} = {{\sin^{- 1}\left( {Y_{w}/L_{bs}} \right)}\quad{or}}}},$

where L_(bs)=L_(b) sin θ_(b).

Referring to FIG. 26, the sine rule is used to determine the insertionlength L_(s) of the instrument. Given the desired position of the tool'swrist joint, the distance from the insertion point to the wrist joint,L_(ws) is simplyL _(w) =√{square root over (X _(w) ² +Y _(w) ² +Z _(w) ² )}

Then by the sine rule, the angle θ_(a) is${{\theta_{a} = {\arcsin\left( {\frac{L_{b}}{L_{w}}\sin\quad\theta_{b}} \right)}},{{{and}\quad L_{s}} = {{{L_{w}\left( \frac{\sin\quad\theta_{c}}{\sin\quad\theta_{b}} \right)}\quad{where}\quad\theta_{c}} = {\theta_{b} - \theta_{a}}}}}\quad$

Having determined ω and L_(s), the last joint angle Ψ can be found fromthe projection of the instrument on the x-z plane as shown in FIG. 27.$\quad\begin{matrix}{{\theta_{\Delta} = {\arccos\left( \frac{L_{s} + {L_{b}\cos\quad\theta_{b}}}{L_{w}^{\prime}} \right)}},} \\{{\theta_{L_{w}^{\prime}} = {\arcsin\left( \frac{X_{wo}}{L_{w}^{\prime}} \right)}},} \\{L_{w}^{\prime} = \sqrt{X_{w}^{2} + {Z_{w}^{2}}^{\quad}}}\end{matrix}$and  X_(wo)  is  the  x-axis  wrist  position  in  referencecoordinate  frame.  

2. Orientation

The last step in kinematic computation for controlling the instrument isdetermining the appropriate joint angles of the tool such that itsorientation is identical to that of the surgeon's interface handle. Inother words, the transformation matrix of the tool must be identical tothe transformation matrix of the interface handle, R_(h).

The orientation of the tool is determined by pitch (θ_(f)), yaw (θ_(wf))and roll (θ_(af)) joint angles as well as the joint angles ω and Ψ, asshown in FIG. 28. First, the starting coordinate is rotated (θ_(b) −π/2)about the y-axis to be aligned with the reference coordinate,represented by the transformation matrix R_(o)$R_{o} = \left\lbrack \quad\begin{matrix}{\sin\quad\theta_{b}} & 0 & \left( {{- \cos}\quad\theta_{b}} \right) \\0 & 1 & 0 \\{\cos\quad\theta_{b}} & 0 & {\sin\quad\theta_{b}}\end{matrix}\quad \right\rbrack$

The wrist joint coordinate is then rotated about the referencecoordinate by angles (−Ψ) about the y-axis and ω about the z-axis,resulting in the transformation matrix R_(w′f),$\quad{R_{w^{\prime}f} =_{\quad}\left\lbrack \quad\begin{matrix}{\cos\quad{\Psi cos}\quad\omega} & \left( {{- \cos}\quad\Psi\quad\sin\quad\omega} \right) & \left( {{- \sin}\quad\Psi} \right) \\{\sin\quad\omega} & {\cos\quad\omega} & 0 \\{\sin\quad\Psi\quad\cos\quad\omega} & \left( {{- \sin}\quad{\Psi sin}\quad\omega} \right) & {\cos\quad\Psi}\end{matrix}\quad \right\rbrack}$

followed by rotation of (π/2−θ_(b)) about the y-axis, represented byR_(wfw′f). $R_{{wfw}^{\prime}f} = {\left\lbrack \quad\begin{matrix}{\sin\quad\theta_{b}} & 0 & {\cos\quad\theta_{b}} \\0 & 1 & 0 \\{{- \cos}\quad\theta_{b}} & 0 & {\sin\quad\theta_{b}}\end{matrix}\quad \right\rbrack\quad{which}\quad{is}\quad{equal}\quad{to}\quad{R_{o}^{T}.}}$

Finally, the tool rolls (−θ_(af)) about the x-axis, yaws θ_(wf) aboutthe z-axis and pitches (−θ_(f)) about the y-axis with respect to thewrist coordinate, are calculated resulting in transformation matrixR_(fwf) $R_{fwf} = \left\lbrack \quad\begin{matrix}R_{fwf11} & R_{fwf12} & R_{fwf13} \\R_{fwf21} & R_{fwf22} & R_{fwf23} \\R_{fwf31} & R_{fwf32} & R_{fwf33}\end{matrix}\quad \right\rbrack$

where R_(fwf11)=cos θ_(wf) cos θ_(f)

R_(fwf12)=−sin θ_(wf)

R_(fwf13)=−cos θ_(wf) sin θ_(f)

R_(fwf21)=cos θ_(af) sin θ_(wf) cos θ_(f)+sin θ_(af) sin θ_(f)

R_(fwf22)=cos θ_(af) cos θ_(wf)

R_(fwf23)=−cos θ_(af) sin θ_(wf) sin θ_(f)+sin θ_(af) cos θ_(f)

R_(fwf31)=−sin θ_(af) sin θ_(wf) cos θ_(f)+cos θ_(af) sin θ_(f)

R_(fwf32)=−sin θ_(af) cos θ_(wf)

R_(fwf33)=sin θ_(af) sin θ_(wf) sin θ_(f)+cos θ_(af) cos θ_(f)

Therefore the transformation matrix of the tool R_(f) with respect tothe original coordinate is

R_(f)=R_(o)R_(wf′)R_(o) ^(T)R_(fwf).

Since R_(f) is identical to R_(h) of the interface handle, R_(fwf) canbe defined by

R_(fwf)=R_(o)R_(wf′) ^(T)R_(o) ^(T)R_(h)=R_(c)$R_{fwf} = {{R_{o}R_{wf}^{T}R_{o}^{T}R_{h}} = {R_{c} = \left\lbrack \quad\begin{matrix}R_{c11} & R_{c12} & R_{c13} \\R_{c21} & R_{c22} & R_{c23} \\R_{c31} & R_{c32} & R_{c33}\end{matrix}\quad \right\rbrack}}$

where the matrix R_(c) can be fully computed with known values. Usingthe computed values of R_(c) and comparing to the elements of R_(fwf),we can finally determine the necessary joint angles of the tool.$\begin{matrix}{{\theta_{wf} = {\arcsin\left( {- R_{c\quad 12}} \right)}},} \\{\theta_{f} = {{\arccos\left( \frac{R_{c\quad 11}}{\cos\quad\theta_{wf}} \right)} = {\arcsin\left( \frac{- R_{c\quad 13}}{\cos\quad\theta_{wf}} \right)}}} \\{\theta_{af} = {{\arccos\left( \frac{R_{c\quad 22}}{\cos\quad\theta_{wf}} \right)} = {\arcsin\left( \frac{- R_{c\quad 32}}{\cos\quad\theta_{wf}} \right)}}}\end{matrix}$

The actuators, which are motors in the current embodiment, are theninstructed to move to positions such that the determined joint anglesand insertion length are achieved.

Now reference is made to the following algorithm that is used inassociation with the system of the present invention. First arepresented certain definitions.

Variable Definitions: (RH - Right Hand, LH - Left Hand) s_Ls_RH Linearslider joint for RH slave s_Xi_RH Lateral motion joint for RH slave (bigdisk in front of slider) s_Omega_RH Up/down motion joint for RH slave(rotates curved tube) s_Axl_RH Axial rotation joint for RH slave(rotates instrument insert along its axis) s_f1_RH Finger 1 for RH slaves_f2_RH Finger 2 for RH slave s_wrist_RH Wrist joint for RH slavem_base_RH Base rotation joint for RH master m_shoulder_RH Shoulder jointfor RH master m_elbow_RH Elbow joint for RH master m_Axl_RH Axialrotation joint for RH master m_f1_RH Finger 1 for RH master m_f2_RHFinger 2 for RH master m_wrist_RH Wrist joint for RH master Radian[i]Motor axle angle for joint no. i with i being one of above jointsDes_Rad[i] Desired motor axle angle for joint no. i Des_Vel[i] Desiredmotor axle angular velocity for joint no. i Mout_f[i] Motor commandoutput for joint no. i Thetabp1_m_RH Angle of base rotation joint for RHmaster Theta2_m_RH Angle of elbow joint for RH master Theta3_m_RH Angleof shoulder joint for RH master Xw_m_RH Position of RH master handle inX-axis Yw_m_RH Position of RH master handle in Y-axis Zw_m_RH Positionof RH master handle in Z-axis Xwref_m_RH Reference position of RH masterhandle in X-axis Ywref_m_RH Reference position of RH master handle inY-axis Zwref_m_RH Reference position of RH master handle in Z-axisPhi_f_m_RH Angle of wrist joint for RH master Theta_f1_m_RH Angle offinger 1 for RH master Theta_f2_m_RH Angle of finger 2 for RH masterThetaAxl_m_RH Angle of axial rotation joint for RH master Theta_h_m_RHAngle of mid line of fingers for RH master Theta_f_m_RH Angle of fingersfrom the mid line for RH master Xw_s_RH Position of RH slave in X-axisYw_s_RH Position of RH slave in Y-axis Zw_s_RH Position of RH slave inZ-axis Xwref_s_RH Reference position of RH slave in X-axis Ywref_s_RHReference position of RH slave in Y-axis Zwref_s_RH Reference positionof RH slave in Z-axis alpha Master-to-slave motion scaling factorXw_s_b1_RH Motion boundary 1 of RH slave in X-axis Xw_s_b2_RH Motionboundary 2 of RH slave in X-axis Yw_s_b1_RH Motion boundary 1 of RHslave in Y-axis Yw_s_b2_RH Motion boundary 2 of RH slave in Y-axis

Note the motion boundaries of the slave are used to define the virtualboundaries for the master system, and do not directly impose boundarieson the slave system.

The following represents the steps through which the algorithm proceeds.

1. The system is started, and the position encoders are initialized tozero. This ASSUMES that the system started in predefined configuration.

/* Preset Encoder Position for all axis */ for(i=0; i<32; ++i) {SetEncoder[i]=0; } /* Convert encoder count to radian */for(i=0;i<32;i++) { Radian[i] = Enc_to_Rad(Encoder[i]); }

2. Bring the system to operating positions, Des_Rad[i], and hold thepositions until the operator hits the keyboard, in which case theprogram proceeds to next step.

While(!kbhit()) { for(i=0;i<14;i++) /* compute motorout for slaverobots*/ { Des_Vel[i]= 0.0; Err_Rad[i] = Des Rad[i] − Radian[i];Err_Vel[i] = Des Vel[i] − Velocity[i]; kpcmd = Kp[i]*Err_Rad[i]; kdcmd =(Kp[i]*Td[i])*Err_Vel[i]; Mout_f[i] =kpcmd + kdcmd;/* Command output tomotor */ } for(i=14;i<28;i++) /* compute motorout for master robot */ {Des_Vel[i] = 0.0; Err_Rad[i] = Des_Rad[i] − Radian[i]; Err_Vel[i] =Des_Vel[i] − Velocity[i]; kpcmd = Kp[i]*Err_Rad[i]; kdcmd =(Kp[i]*Td[i]) *Err_Vel[i]; Mout_f[i] = kpcmd + kdcmd;/* Command outputto motor */ } }

3. Based on the assumption that the system started at the predefinedconfiguration, the forward kinematic computations are performedrespectively for the master and the slave systems to find the initialpositions/orientations of handles/tools.

/* Compute Initial Positions of Wrist for Right Hand Master */

Thetabp1o_m_RH =−Radian[m_base_RH]/PR_bp1;

Theta3o_m_RH=−Radian[m_shoulder_RH]/PR_(—)3;

Thetabp1_m_RH =Thetabp1o_m_RH;

Theta3_m_RH=Theta3o_m_RH;

Theta2o_m_RH =Theta3o_m_RH−Radian[m_elbow_RH]/PR_(—)2;

Theta2_m_RH=Theta2o_m_RH;

Theta2A_m_RH=(Theta2_m_RH−Theta3_m_RH);

Theta2A_eff_m_RH=Theta2A_m_RH+Theta_OS_m;

L_m_RH=(L3_m*sin(Theta3o_m_RH)+L2_eff_m*cos(Theta2A_eff_m_RH));

Xwo_m_RH=L_m_RH*cos(Thetabp1o_m_RH);

Ywo_m_RH=−(L3_m+L2_eff m*sin(Theta2A_eff_m_RH));

Zwo_m_RH=L_m_RH*sin(Thetabp1o_m_RH);

/* Set these initial positions as the reference positions. */

Xwref_m_RH=Xwo_m_RH=L2 (FIG. 23)

Ywref_m_RH=Ywo_m_RH=L3

Zwref_m_RH=Zwo_m_RH=0

/* Initial Position of the Wrist for Right Hand Slave based onpredefined configurations */

Ls_RH=Ls;

Xwo_s_RH=Lbs=X ref_s_RH

Ywo_s_RH=0.0=Yref_s_RH

Zwo_s_RH=—(Ls_RH+Lbc)=Zref_s_RH

/* Compute Initial Orientations for Right Hand Handle */

Phi_f_m_RH=Radian[m_wrist_H];

Theta_f1_m_RH=Radian[m_f1_RH];

Theta_f2_m_RH=−Radian[m_f2_RH]−Theta_f1_m_RH;

ThetaAx1_m_RH=Radian[m_Ax1_RH];

Theta_h_m_RH=(Theta_f1_m_RH−Theta_f2_m_RH)/2.0; /* angle of midline

Theta_f_m_RH=(Theta_f1_m_RH+Theta_f2_m_RH)/2.0; /* angle of finger frommid line */

/* Repeat for Left Hand Handle and Slave Instrument */

4. Repeat the procedure of computing initial positions/orientations ofhandle and tool of left hand based on predefined configurations.

5. Read starting time

/* Read starting time: init_time */

QueryPerformanceCounter(&hirescount);

dCounter=(double)hirescount.LowPart+(double)hirescount.HighPart *(double)(4294967296);

QueryPerformanceFrequency(&freq);

init_time=(double)(dCounter/freq.LowPart);

prev_time=0.0;

6. Read encoder values of master/slave system, and current time

/* Read encoder counters */ for(i=1; i<9; ++i) { Read_Encoder(i); } /*Convert encoder counts to radian */ for(i=0;i<32;i++) { Radian[i] =Enc_to_Rad(Encoder[i]); } /* Get current time */QueryPerformanceCounter(&hirescount); dCounter =(double)hirescount.LowPart + (double)hirescount.HighPart *(double)(4294967296); time_now = (double)(dCounter/freq.LowPart) −init_time; delta_time3 = delta_time2; delta_time2 = delta_time1;delta_time1 = time_now − prev_time; prev_time = time_now;

7. Compute current positions/orientations of master handle for RightHand

/* Compute master handle's position for right hand */

Thetabp1_m_RH=−Radian[m_base_RH]/PR_bp1;

Theta3_m_RH=−Radian[m_shoulder_RH]/PR_(—)3;

Theta2_m_RH=Theta3_m_RH−Radian[m_elbow_RH]/PR_(—)2;

Theta2A_m_RH=(Theta2_m_RH−Theta3_m_RH);

Theta2A_eff_m_RH=Theta2A_m_RH+Theta_OS_m;

L_m_RH=(L3_m*sin_Theta3_m+L2_eff_m*cos_Theta2A_eff_m);

Xw_m_RH=L_m_RH*cos_Thetabp1_m;

Yw_m_RH=−(L3_m*cos_Theta3_m+L2_eff_m*sin_Theta2A_eff_(s —)m);

Zw_m_RH=L_m_RH*sin_Thetabp1_m;

/* Compute master handle's orientation for right hand */

Phi_f_m_RH=Radian[m_wrist_RH];

Theta_f₁_m_RH=Radian[m_f1_RH];

Theta_f2_m_RH=−Radian[m_f2_RH]−Theta_f1_m_RH;

ThetaAx1_m_RH=Radian[m_Ax1_RH];

Theta_h_m_RH=(Theta_f1_m_RH−Theta_f2_m_RH)/2.0; /* angle of midline */

Theta_f_m_RH=(Theta_f1_m_RH+Theta_f2_m_RH)/2.0; /* angle of fingers frommid line */

/* Perform coordinate transformation to handle's coordinate */

Rwh11=cos_Thetabp1_m*cos_Theta2A_m;

Rwh12=−sin_Thetabp1_m*sin_ThetaAx1_m+cos_Thetabp1_m*sin_Theta2A_m*cos_ThetaAx1_m;

Rwh13=−sin_Thetabp1_m*cos_ThetaAx1_m−cos_Thetabp1_m*sin_Theta2A_m*sin_ThetaAx1_m;

Rwh21=−sin_Theta2A_m;

Rwh22=cos_Theta2A_m*cos_ThetaAx1_m;

Rwh23=−cos_Theta2A_m*sin_ThetaAx1_m;

Rwh31=sin_Thetabp1_m*cos_Theta2A_m;

Rwh32=cos_Thetabp1_m*sin_ThetaAx1_m+sin_Thetabp1_m*sin_Theta2A_m*cos_ThetaAx1_m;

Rwh33=cos_Thetabp1_m*cos_ThetaAx1_m−sin_Thetabp1_m*sin_Theta2A_m*sin_ThetaAx1_m;

Rhr11=cos_Phi_f_m*cos_Theta_h_m;

Rhr12=−sin_Phi_f_m;

Rhr13=−cos_Phi_f_m*sin_Theta_h_m;

Rhr21=sin_Phi_f_m*cos_Theta_h_m;

Rhr22=cos_Phi_f_m;

Rhr23=−sin_Phi_f_m*sin_Theta_h_m;

Rhr31=sin_Theta_h_m;

Rhr32=0.0;

Rhr33=cos_Theta_h_m;

Rh11=Rwh11*Rhr11+Rwh12*Rhr21+Rwh13 *Rhr31;

Rh12=Rwh11*Rhr12+Rwh12*Rhr22+Rwh13*Rhr32;

Rh13=Rwh11*Rhr13+Rwh12*Rhr23+Rwh13*Rhr33;

Rh21=Rwh21*Rhr11+Rwh22*Rhr21+Rwh23*Rhr31;

Rh22=Rwh21*Rhr12+Rwh22*Rhr22+Rwh23*Rhr32;

Rh23=Rwh21*Rhr13+Rwh22*Rhr23+Rwh23*Rhr33;

Rh31=Rwh31*Rhr11+Rwh32*Rhr21+Rwh33*Rhr31;

Rh32=Rwh31*Rhr12+Rwh32*Rhr22+Rwh33*Rhr32;

Rh33=Rwh31*Rhr13+Rwh32*Rhr23+Rwh33*Rhr33;

8. Desired tool position is computed for right hand

/* Movement of master handle is scaled by alpha for tool position */

Xw_s_RH=alpha*(Xw_m_RH−Xwref_m_RH)+Xwref_s_RH;

Yw_s_RH=alpha*(Yw_m_RH−Ywref_m_RH)+Ywref_s_RH;

Zw_s_RH=alpha*(Zw_m_RH−Zwref_m_RH)+Zwref_s_RH;

/* The next step is to perform a coordinate transformation from thewrist coordinate (refer to FIG. 25 and coordinate Xwf, Ywf and Zwf) to acoordinate aligned with the tube arm Ls. This is basically a fixed 45°transformation (refer in FIG. 25 to θ_(b)) involving the sin and cos ofθ_(b) as expressed below. */

Xwo_s_RH=Xw_s_RH*sin_Theta_b+Zw_s_RH*cos_Theta_b;

Ywo_s_RH=Yw_s_RH;

Zwo_s_RH=−Xw_s_RH*cos_Theta_b+Zw_s_RH*sin_Theta_b;

9. Perform inverse kinematic computation for the right hand to obtainnecessary joint angles of the slave system such that toolposition/orientation matches that of master handle.

Omega_RH=asin(Ywo_s_RH/Lbs);

Lw=sqrt(pow(Xwo_s_RH,2)+pow(Ywo_s_RH,2)+pow(Zwo_s_RH,2));

Theta_a=asin(Lb/Lw*sin_Theta_b);

Theta_c=Theta_b−Theta_a;

Ls_RH=Lw*(sin(Theta_c)/sin_Theta_b);

Lwp=sqrt(pow(Lw,2)−pow(Ywo_s_RH,2));

Theta_Lwp=asin(Xwo_s_RH/Lwp);

Xi_RH=Theta_Lwp−Theta_delta;

sin_Omega=sin(Omega_RH);

cos_Omega=cos(Omega_RH);

sin_Xi=sin(Xi_RH);

cos_Xi=cos(Xi_RH);

Ra11=cos_Xi*cos_Omega*sin_Theta_b+sin_Xi*cos_Theta_b;

Ra12=sin_Omega*sin_Theta_b;

Ra13=sin_Xi*cos_Omega*sin_Theta_b−cos_Xi*cos_Theta_b;

Ra21=−cos_Xi*sin_Omega;

Ra22=cos_Omega;

Ra23=−sin Xi*sin_Omega;

Ra31=cos_Xi*cos_Omega*cos_Theta_b−sin_Xi*sin_Theta_b;

Ra32=sin_Omega*cos_Theta_b;

Ra33=sin_Xi*cos_Omega*cos_Theta_b+cos_Xi*sin_Theta_b;

Rb11=Ra11*sin_Theta_b−Ra13*cos_Theta_b;

Rb12=Ra12;

Rb13=Ra11*cos_Theta_b+Ra13*sin_Theta_b;

Rb21=Ra21*sin_Theta_b−Ra23*cos_Theta_b;

Rb22=Ra22;

Rb23=Ra21*cos_Theta_b+Ra23*sin_Theta_b;

Rb31=Ra31*sin_Theta_b−Ra33*cos_Theta_b;

Rb32=Ra32;

Rb33=Ra31*cos_Theta_b+Ra33*sin_Theta_b;

Rc11=Rb11*Rh11+Rb12*Rh21+Rb13*Rh31;

Rc12=Rb11*Rh12+Rb12*Rh22+Rb13*Rh32;

Rc13=Rb11*Rh13+Rb12*Rh23+Rb13*Rh33;

Rc21=Rb21*Rh11+Rb22*Rh21+Rb23*Rh31;

Rc22=Rb21*Rh12+Rb22*Rh22+Rb23*Rh32;

Rc23=Rb21*Rh13+Rb22*Rh23+Rb23*Rh33;

Rc31=Rb31*Rh11+Rb32*Rh21+Rb33*Rh31;

Rc32=Rb31*Rh12+Rb32*Rh22+Rb33*Rh32;

Rc33=Rb31*Rh13+Rb32*Rh23+Rb33*Rh33;

sin_Theta_wf_s=−Rc12;

Theta_wf_s_RH=asin(sin_Theta_wf_s);

cos_Theta_wf_s=cos(Theta_wf_s_RH);

/* Compute Theta_f_s_RH */

var1=Rc11/cos_Theta_wf_s;

var2=−Rc13/cos_Theta_wf_s;

Theta_f_s_RH=asin(var2) or acos(var1) depending or region;

/* Compute ThetaAx1_s_RH */

var1=Rc22/cos_Theta_wf_s;

var2=−Rc32/cos_Theta_wf_s;

ThetaAx1_s_RH=asin(var2) or acos(var1) depending or region;

10. Repeat steps 7-9 for left hand system

11. Determine motor axle angles necessary to achieve desiredpositions/orientations of the slave systems, and command the motors tothe determined positions.

Des_Rad[s_Ls_RH] = 63.04*(Ls_RH-Ls_init_RH − 0.75*(Xi_RH-Xi_init_RH));Des_Rad[s_Xi_RH] = −126.08*(Xi_RH-Xi_init_RH); Des_Rad[s_Omega_RH] =−23.64*(Omega_RH-Omega_init_RH); Des_Rad[s_Axi_RH] =−23.64*1.3333*(ThetaAxl_s_RH + Omega_RH- Omega_init_RH);Des_Rad[s_wrist_RH] = 18.9*Theta_wf_s_RH; Des_Rad[s_f1_RH] =18.9*(Theta_f_s_RH + Theta_f_m_RH); Des_Rad[s_f2_RH] =18.9*(−Theta_f_s_RH + Theta_f_m_RH); Des_Rad[s_Ls_LH] =−63.04*(Ls_LH-Ls_init_LH − 0.75*(Xi_LH-Xi_init_LH)), Des_Rad[s_Xi_LH] =126.08*(Xi_LH-Xi_init_LH); Des_Rad[s_Omega_LH] =−23.64*(Omega_LH-Omega_init_LH); Des_Rad[s_Ax1_LH] =−23.64*1.3333*(ThetaAxl_s_LH + Omega_LH- Omega_init_LH);Des_Rad[s_wrist_LH] = 18.9*Theta_wf_s_LH; Des_Rad[s_f1_LH] =−18.9*(−Theta_f_s_LH − Theta_f_m_LH); Des_Rad[s_f2_LH] =−18.9*(Theta_f_s_LH − Theta_f_m_LH); /* Compute motor output for slavesystems */ for(i=0;i<14;i++) { Des_Vel[i] = 0.0; Err_Rad[i] = Des_Rad[i]− Radian[i]; Err_Vel[i] = Des_Vel[i] − Velocity[i]; kpcmd =Kp[i]*Err_Rad[i]; kdcmd = (Kp[i]*Td[i])*Err_Vel[i]; Mout_f[i] = kpcmd +kdcmd; } /* Virtual boundaries for master handles */if(Xwo_s_RH>=Xw_s_b1_RH) { Fx_RH = 3.0*k_master*(Xwo_s_RH-Xw_s_b1_RH);Mout_f[m_base_RH] = Fx_RH*cos(0.7854−(Radian[m_base_RH]/14.8));Mout_f[m_shoulder_RH] = Fx_RH*sin(0.7854− (Radian[m_base_RH]/14.8))−1.0*Radian[m_shoulder RH]; } else if (Xwo_s_RH<=Xw_sb2_RH) { Fx_RH =k_master*(Xwo_s_RH-Xw_s_b2_RH); Mout_f[m_base_RH] =Fx_RH*cos(0.7854−(Radian[m_base_RH]/14.8)); Mout_f[m_shoulder_RH] =Fx_RH*sin(0.7854− (Radian[m_base_RH]/14.8))− 1.0*Radian[m_shoulder_RH];} else { Mout_f[m_base_RH]=0.0;Mout_f[m_shoulder_RH]=−1.0*Radian[m_shoulder_RH]; }if(Ywo_s_RH>=Yw_s_b2_RH) { Mout_f[m_elbow_RH] =−k_master*(Ywo_s_RH-Yw_s_b2_RH); } else if (Ywo_s_RH<=Yw_s_b1_RH) {Mout_f[m_elbow_RH] =−k_master*(Ywo_s_RH-Yw_s_b1_RH); } elseMout_f[m_elbow_RH]=0.0; /* Repeat for left master handle */

12. Go back to step 6 and repeat.

Previously there has been described an algorithm for providingcontrolled operation between the master and slave units. The followingdescription relates this operation to the system of FIGS. 1-2.

The controller 9 receives input signals from the input device 3 thatrepresent the relative positions of the different portions of the inputdevice. These relative positions are then used to drive the instrument14 to a corresponding set of relative positions. For example, the inputdevice includes a base 50 (FIG. 2A) to which a first link 90 isrotatably connected. A second link 96 is rotatably connected to thefirst link at an elbow joint 94. Connected to the second link 96opposite the elbow joint 94 is a wrist joint 98A and two fingers. Asurgeon may attach a thumb and forefinger to the two fingers and movethe input device to drive the instrument 14.

As the surgeon operates the input device, rotational position of thebase (Thetabp1_m_RH), the rotational position of the first link relativeto the base (Theta3_m_RH), the rotational position of the second linkrelative to the first link (Theta2_m_RH), the angle of the wrist jointrelative to the second link (PHI_f_m_RH, i.e., the angle the wrist jointis rotated about an axis perpendicular to the length of the secondlink), the rotary angle of the wrist joint relative to the second link(ThetaAx1_m_RH, i.e., the angle the wrist joint is rotate about an axisparallel to the length of the second link), and the angles of thefingers (Theta_f1_m_RH and Theta_f2_m_RH) are provided to thecontroller.

When the surgical instrument is first started, the controllerinitializes all of the position encoders in the instrument 14 and theinput device 3, assuming that the system has been started in a desiredinitial configuration. See Sections 1-3 of the algorithm. The initialposition of the input device, e.g., Xwo_m_RH, Ywo_m_RH, and Zwo_m_RH, isthen used to establish a reference position for the input device,Xwref_m_RH, Ywref_m_RH, and Zwref_m_RH. See Section 3 of the algorithm.Initial positions are also established for the instrument 14 based onthe dimensions of the instrument 14. See Section 3 of the algorithm.

With reference to Section 3 of the algorithm, it is noted that there isan assignment of the initial position of the wrist for the slave, andthat this is not a forward kinematics calculation based upon jointangles, but rather is a number based upon the predefined configurationof the slave unit. The coordinate of the slave relates to fixed physicaldimensions of the instrument and instrument holder.

As the surgeon moves the input device 3, the encoder values for theinput device are read and used to compute the current absolute positionof the input device, i.e., Xw_m_RH Yw_m_RH and Zw_m_RH. See Sections 6and 7 of the algorithm. The controller then determines the desiredposition of the tool 18 (Xw_s_RH, Yw_s_RH, and Zw_s_RH) base on thecurrent position of the input device (Xw_m_RH Yw_m_RH, and Zw_m_RH), thereference position for the input device (Xwref_m_RH, Ywref_m_RH, andZwref_m_RH) and the reference position for the instrument 14(Xwref_s_RH, Ywref_s_RH, and Zwref_s_RH). See Section the algorithm. Thedesired position of the tool 18 (Xw_s_RH, Yw_s_RH, and Zw_s_RH) is thentransformed by a 45° coordinate transformation giving the desiredposition (Xwo_s_RH, Ywo_s_RH, Zwo_s_RH) which is used to determine jointangles and drive motor angles for the instrument 14 orientation to matchthat of the input device. See Sections 8-11 of the algorithm. Thus,movement of the surgical instrument 14 is determined based on thecurrent absolute position of the input device, as well as the initialpositions of the input device and the instrument at the time of systemstart-up.

E. Select Features of Described Embodiment

The control in accordance with the present embodiment, as exemplified bythe foregoing description and algorithm, provides an improvement instructure and operation while operating in a relatively simple manner.For example, the control employs a technique whereby the absoluteposition of the surgeon input device is translated into control signalsto move the instrument to a corresponding absolute position. Thistechnique is possible at least in part because of the particularconstruction of the instrument and controllable instrument holder, whichessentially replace the cumbersome prior art multi-arm structuresincluding one or more passive joints. Here there is initialized an allactive joint construction, including primarily only a single instrumentholder having a well-defined configuration with respect to the insertedinstrument.

Some prior-art systems rely upon passive joints to initially positionthe distal tip of the surgical instrument. Because the positions of thepassive joints are initially unknown, the position of the distal tip ofthe surgical instrument with respect to the robot (instrument holder) isalso unknown. Therefore, these systems require an initial calculationprocedure. This involves the reading of joint angles and the computationof the forward kinematics of all elements constituting the slave. Thisstep is necessary because the joint positions of the slave areessentially unknown at the beginning of the procedure.

On the other hand, in accordance with the present invention it is notnecessary to read an initial position of joint angles in order todetermine an initial position of the distal tip of the surgicalinstrument. The system of the present invention, which preferablyemploys no passive joints, has the initial position of the distal tip ofthe surgical instrument known with respect to the base of theinstrument. The instrument is constructed with known dimensions, such asbetween base pivot 225 and the wrist (303 at axis 306 in FIG. 2D) of thetool 18. Further, the instrument is initially inserted by the surgeon ina known configuration, such as illustrated in FIGS. 9 and 10, where thedimensions and orientations of the instrument insert and adaptor guidetube are known with respect to the base (pivot 225). Therefore, aninitial position of the surgical instrument distal tip need not becalculated before the system is used.

The system of the present embodiment is fixed to the end of a staticmount (bracket 25 on post 19) which is manually maneuvered over thepatient, such as illustrated in FIG. 1. Since the initial position ofthe surgical instrument tip (tool 18) with respect to the base (pivot225) of the articulate mechanism is invariant, the joint positions areneither read nor is the forward kinematics computed during the initialsetup. Thus, the initial position of the surgical instrument tip isneither computed nor calculated. In addition, because the base of thesystem in accordance with the present embodiment is not necessarilyfixed directly to the surgical table, but rather movable during asurgical procedure, the initial position of the surgical instrument in aworld coordinate system is not knowable.

Another advantage of the present system is that the instrument does notuse the incision in the patient to define a pivot point of theinstrument. Rather, the pivot point of the instrument is defined by thekinematics of the mechanism, independent of the patient incision, thepatient himself, or the procedure. Actually, the pivot point in thepresent system is defined even before the instrument enters the patient,because it is a pivot point of the instrument itself. This arrangementlimits trauma to the patient in an area around the incision.

From an illustrative standpoint, the base of the instrument may beconsidered as pivot 225 (FIG. 8), and the wrist may be the pivotlocation 604 (axis) depicted in FIG. 16B (or axis 306 in FIG. 2D). Theguide tube 17 has known dimensions and because there are no other joints(active or passive) between the pivot 225 and wrist joint, all of theintervening dimensions are known. Also, the instrument when placed inposition has a predefined configuration such as that illustrated inFIGS. 1, 9 and 10 with the guide tube flat is one plane.

The guide tube 17 may also have an alignment mark therealong essentiallyin line with the pivot 225, as shown in FIG. 9. This marks the locationwhere the guide tube 17 is at the patient incision point. The result isminimal trauma to the patient occasioned by any pivoting action aboutpivot 225.

Another advantage is the decoupling nature of the present system. Thisdecoupling enables the slave unit to be readily portable. Here theinstrument, drive unit and controller are decouplable. A sterilizedadaptor 15 is inserted into a patient, then coupled to a non-steriledrive unit 8 (outside the sterile field). Instrument inserts 16 are thenremovably attached to the surgical adaptor to perform the surgicalprocedure. The system of the present embodiment separates the drive unit8 from the instruments 16. In this way, the instruments can bemaintained as sterile, but the drive unit need not be sterilized.Furthermore, at the time of insertion, the adaptor 15 is preferablydecoupled from the drive unit 8 so it can be readily manually maneuveredto achieve the proper position of the instrument relative to the patientand the patient's incision.

In accordance with the present embodiment, the instrument inserts 16 arenot connected to the controller 9 by way of any input/output portconfiguration. Rather, the present system employs an exclusivelymechanical arrangement that is effected remotely and includes mechanicalcables and flexible conduits coupling to a remote motor drive unit 8.This provides the advantage that the instrument is purely mechanical anddoes not need to be contained within a sterile barrier. The instrumentmay be autoclaved, gas sterilized or disposed in total or in part.

The present system also provides an instrument that is far less complexthan prior art robotic system. The instrument is far smaller than thatof a typical prior art robotic system, because the actuators (motors)are not housed in the articulate structure in the present system.Because the actuators are remote, they may be placed under the operatingtable or in another convenient location and out of the sterile field.Because the drive unit is fixed and stationary, the motors may be ofarbitrary size and configuration, without effecting the articulatedmechanics. Finally, the design allows multiple, specialized instrumentsto be coupled to the remote motors. This allows one to design aninstrument for particular surgical disciplines including, but notlimited to, such disciplines as cardiac, spinal, thoracic, abdominal,and arthroscopic.

A further important aspect is the ability to make the instrumentdisposable. The disposable element is preferably the instrument insert16 such as illustrated in FIG. 15A. This disposable unit may beconsidered as comprising a disposable, mechanically drivable mechanismsuch as the coupler 300 interconnected to a disposable tool 18 through adisposable elongated tube such as the stem section 301, 302 of theinstrument insert. This disposable implement is mounted so that themechanically drivable mechanism may be connectable to and drivable froma drive mechanism. In the illustrated embodiment the drive mechanism mayinclude the coupler 230 and the associated drive motors. The disposableelongate tube 301, 302 is inserted into an incision or orifice of apatient along a selected length of the disposable elongated tube.

The aforementioned disposable implement is purely mechanical and can beconstructed relatively inexpensively, thus lending itself readily tobeing disposable. Another factor that lends itself to disposability isthe simplicity of the instrument distal end tool (and wrist)construction. Prior tool constructions, whether graspers or other types,are relatively complex in that they usually have multiple pulleys at thewrist location for operation of different degrees-of-freedom there,making the structure quite intricate and relatively expensive tomanufacture. On the other hand, in accordance with the presentinvention, no pulleys are required and the mechanism in the location ofthe wrist and tool is simple in construction and can be manufactured atfar less expense, thus readily lending itself to disposability. One ofthe aspects of the invention that has enabled elimination of thepulleys, or the like, is the decoupling of tool action relative to wristaction by passing the tool actuation cables essentially through thecenter axis (604 in FIGS. 16A and 16B) of the wrist joint. Thisconstruction allows proper wrist action without any significant actionbeing conveyed to the tool cables, and furthermore allows for a verysimple and inexpensive construction at the distal end of the implement.

Another aspect is the relative simplicity of the system, both in itsconstruction and use. This provides an instrument system that is farless complex than prior robotic systems. Furthermore, by enabling adecoupling of the slave unit at the motor array, there is provided areadily portable and readily manually insertable slave unit that can behandled quite effectively by the surgeon or assistant when the slaveunit is to be engaged through a patient incision or orifice. Thisenables the slave unit to be positioned through the incision or orificeso as to dispose the distal end at a target or operative site. A supportis then preferably provided so as to hold a base of the slave unit fixedin position relative to the patient at least during a procedure that isto be carried out. This initial positioning of the slave unit with apredefined configuration immediately establishes an initial referenceposition for the instrument from which control occurs via a controllerand user interface.

This portable nature of the slave unit comes about by virtue ofproviding a relatively simple surgical instrument insert in combinationwith an adaptor for the insert that is of relatively smallconfiguration, particularly compared with prior large articulatedrobotic arm(s) structures. Because the slave unit is purely mechanical,and is decouplable from the drive unit, the slave unit can be readilypositioned by the operator. Once in position, the unit is then securedto the support and the mechanical cables are coupled with the driveunit. This makes the slave unit both portable and easy to position inplace for use.

Another advantage of the system is the ability to position the holder oradaptor for the instrument with its distal end at the operative site andmaintained at the operative site even during instrument exchange. By wayof example, and with reference to FIG. 2B, the instrument holder isrepresented by the guide tube 17 extending to the operative site OS.When instruments are to be exchanged, the distal end of the guide tube17 essentially remains in place and the appropriate instruments aresimply inserted and/or withdrawn depending on the particular procedurethat is being carried out.

Accordingly, one of the advantages is the ease of exchanginginstruments. In a particular operation procedure, there may be amultitude of instrument exchanges and the present system is readilyadapted for quick and easy instrument exchange. Because the holder oradaptor is maintained in position, the surgeon does not have to be ascareful each and every time that he reintroduces an instrument into thepatient. In previous systems, the instrument is only supported through acannula at the area of the incision and when an instrument exchange isto occur, these systems require removal of the entire assembly. Thismeans that each time a new instrument is introduced, great care isrequired to reposition the distal end of the instrument so as to avoidinternal tissue or organ damage. On the other hand, in accordance withthe present invention, because the holder or adaptor is maintained inposition at the operative site, even during instrument exchange, thesurgeon does not have to be as careful as the insert simply slidesthrough the rigid tube adaptor. This also essentially eliminates anychance of tissue or organ damage during this instrument exchange.

Having now described a limited number of embodiments of the presentinvention, it should be apparent to those skilled in the art thatnumerous other embodiments and modifications thereof are contemplated asfalling within the scope of the present invention.

1. A method of controlling a surgical instrument that is inserted in apatient for facilitating a surgical procedure and controlled remotelyfrom an input device manipulated by a surgeon at a user interface, saidmethod comprising the steps of: initializing the position of thesurgical instrument without calculating its initial position, and theposition of the input device under electronic control; said initializingincluding establishing an initial reference position for the inputdevice and an initial reference position for the surgical instrumentcalculating the current position of the input device as it ismanipulated by the surgeon; determining the desired position of thesurgical instrument based upon; the current position of the inputdevice, the initial reference position of the input device, and theinitial reference position of the surgical instrument, and moving thesurgical instrument to the desired position so that the position of thesurgical instrument corresponds to that of the input device.
 2. A methodas set forth in claim 1 wherein the input device has position sensors,and the step of initializing includes these position sensors.
 3. Amethod set forth in claim 2 wherein the initializing is to zero.
 4. Amethod as set forth in claim 1 including computing an initial referenceorientation for the input device.
 5. A method as set forth in claim 4including computing a desired orientation for the surgical instrument.6. A method as set forth in claim 5 including computing a desiredposition for the surgical instrument.
 7. A method as set forth in claim1 wherein said initializing step includes performing a forward kinematiccomputation from the input device.
 8. A method as set forth in claim 2including reading position sensor values and current time.
 9. A methodas set forth in claim 8 wherein the calculating step includescalculating both the position and orientation of the input device.
 10. Amethod as set forth in claim 1 including calculating the currentorientation of the input device.
 11. A method as set forth in claim 1wherein said step of determining includes performing an inversekinematic computation.
 12. A method as set forth in claim 1 wherein saiddetermining step includes a transformation into an earth coordinatesystem.
 13. A method as set forth in claim 12 wherein from saidtransformation there are determined joint angles and drive motor anglesfor the surgical instrument orientation.
 14. A method of controlling atool of a surgical instrument that is inserted in a patient for carryingout a surgical procedure and is controlled remotely by way of anelectronic controller from an input device at a user interface, saidmethod comprising the steps of: setting the input device at an initialreference configuration and under electronic controller control; settingthe surgical instrument in the patient at an initial predefinedreference configuration without electronic controller control;calculating the current absolute position of the input device;determining the desired location of the tool by a kinematic computationthat accounts for at least the initial reference configuration of theinput device and the current absolute position of the input device; andmoving the surgical instrument to the desired position so that thelocation of the tool corresponds to that of the input device.
 15. Amethod as set forth in claim 14 wherein said step of determining is alsobased upon the initial reference configuration of the tool.
 16. A methodas set forth in claim 14 wherein the input device has position sensors,and the step of setting includes initializing these position sensors.17. A method as set forth in claim 14 including computing an initialreference orientation for the input device.
 18. A method as set forth inclaim 14 including computing a desired orientation for the surgicalinstrument.
 19. A method as set forth in claim 14 wherein saidcalculating step includes performing a forward kinematic computationfrom the input device.
 20. A method as set forth in claim 14 includingcalculating the current orientation of the input device.
 21. A method asset forth in claim 14 wherein said step of determining includesperforming an inverse kinematic computation.
 22. A method as set forthin claim 14 wherein said determining step includes a transformation intoan earth coordinate system.
 23. A method as set forth in claim 22wherein from said transformation there are determined joint angles anddrive motor angles for the surgical instrument orientation.
 24. A methodof controlling a medical implement remotely from an input device that iscontrolled by an operator, said method comprising the steps of:positioning the medical implement at an initial start position at anoperative site for the purpose of facilitating a medical procedure;establishing a fixed position reference coordinate representative of theinitial start position of said medical implement based upon a base pointof the implement and an active point of the implement being in aninitial known relative dimensional configuration, positioning the inputdevice at an initial start position; establishing a fixed positionreference coordinate; calculating the current position of the inputdevice as it is controlled; determining the desired position of themedical implement based upon; the current position of the input device,the fixed position reference coordinate of the input device, and thefixed position reference coordinate of the medical implement, and movingthe medical implement to the desired position so that the position ofthe medical implement corresponds to that of the input device.
 25. Amethod as set forth in claim 24 wherein, in said step of positioning themedical implement, the medical implement comprises a surgicalinstrument.
 26. A method as set forth in claim 25 wherein, in said stepof positioning the medical implement, the medical implement comprises acatheter.
 27. A method as set forth in claim 24 wherein said step ofpositioning the medical implement includes physically placing the distalend of the medical implement at the operative site.
 28. A method as setforth in claim 27 wherein said medical implement is placed withoutpre-computation of a coordinate position at which it is placed.
 29. Amethod as set forth in claim 28 wherein said step of positioning themedical implement is only controlled by manual placement without anyelectric pre-computation of a predetermined coordinate position tocontrol the actual placement of the medical implement.
 30. A method asset forth in claim 24, wherein, in said step of positioning the medicalimplement, the medical implement comprises a surgical instrument havinga tool and a wrist, said established reference coordinate correspondingto an initial position of a location on said wrist.
 31. A method as setforth in claim 24 further including providing an electronic controllerfor controlling said medical implement and wherein the step ofpositioning the medical implement includes manually placing the medicalimplement without computation by said controller of an initialcoordinate position.
 32. A method as set forth in claim 24 furtherincluding providing an electronic controller for controlling saidmedical implement and wherein the step of positioning the input deviceincludes initially moving the input device under controller control soas to establish the reference coordinate position of the input device.33. A method as set forth in claim 25 including storing in thecontroller the reference coordinate position of the input device.
 34. Amethod as set forth in claim 24 wherein said step of establishingincludes performing a forward kinematic computation.
 35. A method as setforth in claim 34 wherein said calculating step includes calculatingboth the position and the orientation of the input device.
 36. A methodas set forth in claim 35 wherein said step of determining includesperforming an inverse kinematic computation.
 37. The method as set forthin claim 24 wherein said step of establishing a fixed position referencecoordinate representative of the initial start position of said medicalimplement includes establishing said reference coordinate in relation tothe patients body.
 38. The method as set forth in claim 37 wherein thereference coordinate of the implement is at a predetermined location ofthe patient.
 39. The method as set forth in claim 38 wherein thepredetermined location is at an incision.
 40. The method as set forth inclaim 38 wherein the reference coordinate of the implement correspondsto an internal site of the patient.
 41. The method as set forth in claim40 wherein the reference coordinate of the implement corresponds to asite external of the patient.
 42. The method as set forth in claim 24wherein the step of establishing a fixed position reference coordinaterepresentative of the initial start position of said medical implementincludes aligning an axis of the base point of the medical implementwith an incision in the patient.
 43. The method as set forth in claim 24wherein the step of determining includes performing a coordinatetransformation from the base point to the active point of the implement.44. The method as set forth in claim 43 wherein the coordinate transformis a fixed transform less than 90 degrees.
 45. The method as set forthin claim 44 wherein the fixed transform is on the order of 45 degrees.46. The method as set forth in claim 45 wherein the fixed transform onthe order of 45 degrees corresponds to the curvature of the guide tube.47. A method of controlling a surgical instrument remotely from an inputdevice and by way of an electronic controller, said method comprisingthe steps of: inserting the surgical instrument through an incision inthe patient so as to dispose the distal end of the instrument at aninitial start position; establishing a fixed position referencecoordinate system corresponding to a fixed predefined configuration ofthe surgical instrument at the initial start position of said surgicalinstrument; positioning the input device at an initial start position;establishing a fixed position reference coordinate system representativeof the initial start position of said input device; calculating thecurrent absolute position of the input device as it is controlled;determining the desired position of the surgical instrument based uponthe current absolute position of the input device, and the fixedposition reference coordinate system for the respective surgicalinstrument and input device; and moving the surgical instrument to thedesired position so that the position of the surgical instrumentcorresponds to that of the input device.
 48. A method as set forth inclaim 47 wherein said step of positioning the input device includesinitializing the location of the input device wider control of thecontroller.
 49. A method as set forth in claim 48 wherein said surgicalinstrument is initially positioned without control from said controller.50. A method as set forth in claim 47 wherein the initial start positionis determined only by manual insertion.
 51. A method as set forth inclaim 50 wherein the step of positioning the input device comprisesinitially moving the input device under controller control so as toestablish the reference coordinate position of the input device.
 52. Amethod as set forth in claim 51 including storing in the controller thereference coordinate position of the input device.
 53. A method as setforth in claim 47 wherein said step of calculating includes performing aforward kinematic computation.
 54. A method as set forth in claim 53wherein said calculating step includes calculating both the position andthe orientation of the input device.
 55. A method as set forth in claim54 wherein said step determining includes performing an inversekinematic computation.
 56. A method of controlling a medical implementremotely from an input device and by way of an electronic controller,said method comprising the steps of: inserting the medical implementthrough an incision in a patient so as to dispose the medical implementin a pre-select initial configuration; assigning a fixed initialreference coordinate to a work element of the medical implement basedupon a known dimension between said work element and a base of themedical implement and said preselected initial configuration;positioning the input device at an initial start position; establishinga fixed initial reference coordinate representative of the initial startposition of die input device; calculating the current position of theinput device as it is controlled; determining the desired position ofthe medical implement based upon at least the current position of theinput device; and moving the medical implement so that the positionthereof corresponds to that of the input device.
 57. A method as setforth in claim 56 wherein said step of inserting the medical implementincludes inserting a surgical instrument.
 58. A method as set forth inclaim 56 wherein said step of inserting the medical implement includesinserting a catheter.
 59. A method as set forth in claim 56 wherein saidstep of inserting the medical implement includes inserting a distal endof the medical implement through the incision so as to be disposed at atarget site.
 60. A method as set forth in claim 56 wherein said step ofinserting the medical implement includes placing the medical implementwithout pre-computation of a coordinate position at which it is placed.61. A method as set forth in claim 56 wherein said step of assigningincludes placing the medical implement without pre-computation todetermine a coordinate position.
 62. A method as set forth in claim 56wherein said step of establishing a fixed initial reference coordinatefor the input device includes executing a forward kinematic computationto determine the reference coordinate.
 63. A method as set forth inclaim 62 wherein said step of executing a forward kinematic computationincludes determining both the position and orientation of the inputdevice.
 64. A method as set forth in claim 62 wherein said step ofexecuting a forward kinematic computation includes determining aposition by a geometric calculation.
 65. A method as set forth in claim64 including determining an orientation by a transformation matrix. 66.A method as set forth in claim 56 wherein said step of determiningincludes performing an inverse kinematic computation.
 67. A method asset forth in claim 66 including determining joint angles and insertionlength of the instrument.
 68. A method as set forth in claim 67including determining the instrument orientation.